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Full text of "Electron User - Vol. 1 No. 11 (1984-08)(Database Publications)(GB)"






p * 



-4 Database Publication 






THREE 

ACTION 

GAMES 

Save skydivers 
from meeting a 
watery end . . . 
try your hand 
at bashing a 
brick wall . . . 
face high drama 
at the seaside 






Vol.1 No. 11 August 1984 £1 



* 

How to create 
large letters 
on the Electron 
■ . . plus ways of 
forming user-defined 
characters and 
generating truly 
random numbers 






V<> 




V* 



<* ^ 



X 



THE** 



REPEtf 



Expand 

your Electron. 




Now you can use your Electron computer with, any 
standard printer using MUSHROOM'S new printer 
and user-port interface. 

Bring your Electron up to the same standard as the 
BBC Model B computer printer and user-port into 
which you can plug robot arms, joy sticks or any 
BBC user-port module. 

On the whole range of MUSHROOM modules and 
interfaces, the Electron edge connector is extended 
to give you unrestricted compatibility with any 
other Electron interface. 

ALL MUSHROOM interfaces can be used separately 
or can be combined into the unique MUSHROOM 
ELECTRO-RAK which is conveniently 
connected to the Acorn Electron 
by a short cable. 



This greatly enhances the performance of the 
Electron and turns the system into a computer 
comparable with many larger mini systems and 
as you grow your computer can grow with you! 

Ask for details on: 

* SIDEWAYS ROM CARD 

* A-D JOYSTICK INTERFACE 

*EPROM PROGRAMMER 

♦MUSHROOM 
ELECTRO- 
RAK 




COMPUTERS LIMITED Aston Road, Bedford, Beds MK42 01, J Telephone: (0234) 58303. 
Another Mushroom product from Broadway Electronics. 



CONTENTS 



Vol. 1 No. 11 August 1984 



elect 






News 

All that's new in the 
growing world of l 
the Electron. 

Beginners 

Part 7 of our gentle 
introduction to Basic 
takes STEPs to deal 
with FOR... NEXT 
loops. 






U 



Maths 
Workout 

The problems of random 
number generation 
explored. I U 

Notebook 

How DRAW and MOVE 
combine. Notes on a 
simple program. 1 9 



Ride Tall 

Large letters for the 

Electron. Now 
everyone can see . - 
the display. 1 O 

Sounds 
Exciting 

Weird and wonderful 
sounds for your 
programs. 




Parachute 

Arcadeactionasyou 

try to save the 
skydivers from a * - 
drenching. d."r 

Software 
Surgery 

All you want to know 
about the latest in 
software from our *_ 
frank reviewers. c. ( 



\/,. 




Super-Spell 

Think you're good at 
spelling? Let this 
program test you 

out. 45 



Casting 
Agency 

More shapes from our 
readers to brighten 
your programs. AQ 

Showtime 

Come and meet us at 
the Electron and BBC 

Micro User Show.^Q 



Scrolfer 

A Program to get vour 
messages rr»SZg 
across the screen 30 

Hardware 
Review 

JfSSs a c,ose 'ook 



■*■ 



.— ~v 



•1 

( 



Castles of 
Sand 

T ne seaside comes to 

Sst E r!r tr ° n *"he 
latest game from 

Martin Holfis. QO 



Fast Ellipse 

A speedy graphics 
listing from Mike 

Cook. 56 

Micro 
Messages 

The pages you write 
yourself. A selection 
from our mailbag.C-i 



On your 
Bike 

brinn n i ma !? d PUSh Dik e 

Orings pedal power 
to your micro. qc 

Bookshelf 

Jwo of the latest 
books receive an 

'"-depth analysis. SJ 

knockout 

bal^ b0U ^3g 

Competition 

Show us your talents 

Program 
Probe 

A close look at a 
Program that, takes a 
close look at use? 
defined characters. 42 



oo 



A SUBSCRIPTIONS 
r\ Subscribe now - and 
^-f get Electron User 
delivered to your 
door each month. 



Managing Editor 
Derek Meakin 

Features Editor 
Pete Bibby 

Production Editor 
Peter Glover 

Layout Design 
Heather Sheldrick 

Advertisement Manager 
John Riding 

Advertising Sales 
John Snowden 

Marketing Manager 
Sue Casewell 



Published by Database Publications Ltd 

Europa House, 68 Chester Road, Hazel Grove, Stockport SK7 5NY. 

Telephone: 06 1-456 8383 (Editorial) 061-456 8500 (Advertising) 
Subscriptions: 061-480 0171 Telex: 667664 sharetg. Prestel: 61 4568383. 



Trade distribution in the UK and overseas: 
Contact Steve Fletcher, Circulation Man- 
ager of Database Publications at the 
above address, or telephone him on 
061-480 4153. 

Electron User is an independent publi- 
cation. Acorn Computers Ltd, manufac- 
turers of the Electron, are not responsible 
for any of the articles in this issue or for 
any of the opinions expressed. 



Electron User welcomes program listings 
and articles for publication. Material 
should be typed or computer-printed, and 
preferably double-spaced. Program list- 
ings should be accompanied by cassette 
tape or disc. Please enclose a stamped, 
self- addressed envelope, otherwise the 
return of material cannot be guaranteed. 
Contributions accepted for publication will 
be on an all-rights basis. 



S ubscript ion rates for 
12 issues, post free: 

£12 UK 

£13 Eire OR £16) 

£20 Europe 

£20 Rest of world (surface) 

f.40 Rest of world (airmail) 



e1984 Database Publi- 
cations Ltd. No material 
may be reproduced in 
whole or in part without 
written permission. While 
every care is taken, the 
publishers cannot be held 
legally responsible for any 
errors in articles or listings. 



August 1984 ELECTRON USER 3 





I 





r A 



I 



r A 



I 




r A 



I 












Turning a great idea into a profitable 
idea isn't easy. 

It needs skill, patience and sheer hard 
work. But to be really profitable, it also 
needs the backing of a large, respected 
company. 

At British Telecom we are now 
looking for writers of games and 
educational programs to help us launch a 
new and exciting range of software. 



If we like your idea well send you a 
cheque straightaway as an advance on 
royalties. 

Then we'll package your program, 
advertise it and distribute it with the care 
and attention you'd expect from one of 
Britain's biggest companies. 

So if you'd like to turn your software 
into hard cash, simply send your program, 
on cassette or disk, to 






FIREFLY 

SOFTWARE 



/^•^v British Telecom, 



Wellington House, Upper St. Martins Lane, London WC2H 9DL. 
Tel: 01-379 6755 




Plusl 

games 

snag 



GAMES fans who buy 
Acorn's Plus 1 add-on 
for their Electrons may 
be in for a rude shock. 

It looks as if most 
non-Acornsoft games 
will refuse to run while 
the Plus 1 is attached to 
the micro. 

The problem is that a 
specific joystick routine 
has to be included in the 
game software - and 
Acorn did not release 
details of this to other 
software houses. 

So the independent 
games publishers 
simply went ahead and 
standardised on the 
joystick interface made 
by First Byte, who had 
sent them examples of 
this hardware in 
advance. 

Electron User reader 
Bill Wales bought a Plus 
1 for his children in 
June. But he soon dis- 
covered that he could 
not run two of the kids' 
favourite games — 
"Moonraider" and "Sea 
Wolf". 

Contacted by Elec- 
tron User, the games 
publishers - M icro 
Power and Optima 
Software - said they 
were still waiting for 
Acorn to send them Plus 
1 units for evaluation. 

But an Acorn spokes- 
man said: "The Plus 1 
cannot tell one piece of 
software from another. 
So there is no reason 
why it should affect the 
games". 



High Street sales 

are booming 



ACORN has hit back 
at rumours that all 
may not be well with 
Electron sales by 
ramping up produc- 
tion to 25,000 mach- 
ines a month. 

"The truth of the 
matter is that we are 
selling just as many as 
we can produce", a 
company spokesman 
told Electron User. 

A survey of the lead- 
ing High Street com- 
puter retailing chains - 
W.H. Smith, Boots and 
Dixons - has served to 
support Acorn's claim. 



For it revealed that to 
date the machine is 
enjoying healthy - if so 
far not spectacular — 
sales. But, more impor- 
tantly, the big three all 
predict a boom in Elec- 
tron sales before the end 
of the year. 

Such is Boots con- 
fidence in the machine 
that it is soon to 



increase the number of 
branches where it is sold 
from 40 to 180. 

"It is selling better 
than the Commodore 64 
even now at a time of 
the year when the 
market is generally flat", 
says a company spokes- 
man. 

Over at W.H. Smith, 
marketing manager 



Exit BBC Model A 



AT long last. Acorn have 
confirmed presi stent 
rumours about the 
future of the BBC Micro 
Model A. 

From September 
they will produce no 
more of the cheaper, 
lower specification ver- 
sion of the Model B. 



The disapperance of the 
Model A has been fore- 
cast ever since the 
launch of the Electron 
last September. 

Despite official 
denials, it was obvious 
that the Electron - 
especially when sup- 
plied with expansion 



units - would steal the 
market from the Model 
A. 

As it is, the death of 
the Model A can only be 
good news for Electron 
users. More than any- 
thing else it confirms the 
strength of the Electron 
market. 



John Rowland an- 
nounced that the com- 
pany was selling one 
Electron for every two 
Sinclair Spectrums. 

"Considering the 
machine began to arrive 
in any real quantity at a 
time when market 
demand overall was 
slow, it has done well", 
he said. 

At Dixons head 
office, it was also good 
news for the Electron. 

'It's going quite 
nicely, thanks very 
much", commented 
computer buyer Howard 
Smith. "Once the 
software problem has 
been ironed out, we 
believe the prospects 
will be very good. 

"After all, it's 
software that sells hard- 
ware at the end of the 
day", he said. 



Major boost from add-on 



THE world of Electron 
peripherals looks set to 
be revolutionised with 
the arrival of an as-yet 
nameless add-on. 

Produced by North- 
ern Computers of 
Frodsham and due for 
release in early Septem- 
ber, it promises to take 
the Electron further 



along the road to full 
BBC Micro status than 
any other peripheral. 

Priced at £99, the 
unit contains the 
analogue to digital con- 
verter and parallel prin- 
ter port that are becom- 
ing standard for Electron 
peripherals. 

More importantly, it 



has the 1MHz bus and 
user port beloved of 
BBC Micro hardware 
enthusiasts. It also has a 
speech interface with a 
speech chip and 
four spare ROM sockets. 
As a spokesman for 
Northern Computers 
said, "The interface con- 
tains nearly everything 



the Electron needs to 
give it the stature of a 
BBC Micro". 

The unit will also 
have a connector which 
will allow a disc inter- 
face to be attached. The 
firm would not say when 
this would be available 
but hinted at a pre- 
Christmas launch. 



August 1984 ELECTRON USER 5 





MICRO 




Or^VI*tf> 



, -tl^ 



COMPUTER COMCERTS 






MICRO Olympics, a new 
best selling computer 
game for the Electron 
and the BBC Micro, has 
achieved a media 
breakthrough by being 
the first software pro- 
gram to carry paid-for 
advertising. 

A number of leading 
computer companies 
who saw the program 
being written asked if 
they could buy space on 
the hoardings that sur- 
round the track featured 
in the game. 

Developed by Data- 
base Publications, it 
allows the computer to 



Micro Olympics is 
making the running 



simulate the world's top 
athletes in 11 of the 
main Olympic track and 
field events. 

In all cases-allowing 
for a slight random ele- 
ment - the computer 
achieves the current 
world record. 

Ranging from the 



100 metres to the 
hammer throw, it is 
accurate in all details 
from times to distances. 

Players attempt to 
beat the computer and 
so establish a world 
record of their own. 

"We were a little 
surprised when com- 



panies approached us to 
advertise in the game", 
admits Mike Cowley, a 
spokesman for Data- 
base. "But the more we 
thought about it, the 
more it was obviously a 
good idea. 

"After all, it's the 
norm these days to see 



arenas for major sport- 
ing events carrying huge 
posters promoting com- 
panies. 

"So we decided to 
allow them to buy space 
on our micro hoardings. 
And in doing so, we 
realised we had come in 
first ourselves". 



Taking 

another 

Byte 



FOLLOWING hot on the 
heels of the First Byte 
joystick interface comes 
a new printer interface 
from the same com- 
pany. 

Housed in a small 
plastic box that matches 
the Electron, it slots 
onto the rear edge 
connector at the back of 
the micro. 

It does not interfere 
with normal working, so 
can be left plugged in all 
the time. 

"It's a bit cheaper 
than comparable inter- 
faces", says First Byte's 
Ray Threadgold. "And it 
works with any printer". 

He added that the 
£35 price tag was 
achieved through stan- 
dardisation of parts. 

"This means we can 
bulk-buy the parts and 
pass the saving on to the 
customer". 



HAPPY 
WRITING 






ouse 





WRITING AID FOR TOTS 




A PROGRAM for the 
Electron, "Happy Writ- 
ing" from Bourne Edu- 
cational Software, helps 
children in their first 
steps to writing, 
especially in forming let- 
ters. 

A "Magic Pencil" 
helps children to under- 
stand where to start and 



which direction to take. 
Sound is used as an 
additional guide. 

"Happy Writing" has 
been tried out in 
schools, where it has 
been shown to hold 
childrens' interest. 

The package can be 
used to practise lower 
case or capital letters. 



or a set of words. 

The word list can be 
readily changed, and the 
program features 
proportional spacing of 
words on the screen. 

The program, aimed 
at 3 to 6-year-olds, 
costs £8.95 (cassette). 

A BBC Micro version 
is available on disc. 



Owners' Club extends Electron 



BROADWAY Elec- 
tronics has launched an 
Electron Owners' Club 
giving members priority 
servicing, discounts on 
accessories, and other 
benefits. 

The move follows the 
success of their BBC 
Owners' Club 18 
months ago, which now 
has 1,000 members. 

Members of the new 
club will be able to 
extend their Electron's 
guarantee for a full year. 
This covers all parts, 
labour and servicing. 

Work will be com- 



guarantee 



*./ r 



pleted "while you wait' 
if possible. But if Broad- 
way keep the machine 
more than two days, 
they will loan a replace- 
ment. 

Other benefits of the 
club include 1 per cent 
off hard wa re a nd 
accessories, apart from 
micros, 15 per cent off 
software, 20 per cent off 
blank tapes, a club 
newsletter and special 
offers. 



Membership is 
£28.75 for Electrons 
purchased from Broad- 
way. For Micros bought 
elsewhere, membership 
costs £40.25. 

Managing director 
Paul Vaughan said: 
"Many Acorn guar- 
antees will be expiring 
soon and this is a very 
economical way to 
extend the cover. 

"It can run either 
from the date the 



original warranty runs 
out, or from the date of 
membership. The dis- 
counts cover our range 
of Mushroom add-ons". 

Already available is a 
combined printer and 
user port card. Complete 
with manual and 
software, including a 
screen dump routine, it 
allows the use of prin- 
ters and joysticks. 

On the way are an 
analogue port and an 
extension ROM card, 
opening the door to 
word processors and 
advanced graphics. 



6 ELECTRON USER August 1984 



Northern 
success 

THE Electron and 
BBC Micro User 
Show to be held in 
Manchester from 
August 31 to Sep- 
tember 2 is already 
reported to be a 
runaway success. 

As early as the 
end of June, vir- 
tually all the 90 
stands available in 
the Renold Buil- 
ding at UMISThad 
been snapped up. 

Acorn itself has 
booked an island of 
eight stands for its 
official display 
during the three 
day spectacular. 



Micro Show is set to 

smash records 



THE July Electron 
and BBC Micro 
User Show — the 
first to be held at 
Alexandra Palace, 
London — is set to 
smash all previous 
records. 

Exhibitors have been 
clamouring to book 
space, and the final 
number of standholders 
is forecast to pass the 
140 mark - some 20 
more than the previous 
best. 

Demand for advance 
tickets has also been 
heavy, running way 
ahead of previous pre- 



show sales figures. 

"It looks as though 
we are going to have a 
bonanza", says Mike 
Cowley, spokesman for 
Database Publications, 
the show organisers. 

'This is particularly 
pleasing as some people 
reckoned we had bitten 
off more than we could 
chew with such an 
enormous venue as the 
Alexandra Palace 
Pavilion". 

Even before its open- 



ing three years ago, the 
building was being des- 
cribed by the arch- 
itectural press as "a 
palace of light". 

With an area of 
4,600 square metres, a 
translucent roof 1 5 
metres high spanning 
36 metres, it is the 
largest fabric-covered 
building in Britain. 

Due to this innovative 
design, it provides 
3,620 square metres of 
clear floor space free 



Hare gets top security 



A MAJOR security 
operation is to be 
mounted at the Elec- 
tron and BBC Micro 
User Show in London 
when an interna- 
tionally famed gold 
artefact goes on disp- 
lay. 

Known as the 
"Jewelled Hare of Mas- 
querade", it has recently 
been acquired by a 
London software house 
which has agreed to 
loan it for the duration of 
the three day event. 

Valued at £30,000, it 
will be under round- 
the-clock guard at 
Alexandra Palace, 
where it will provide a 
feature attraction for 
visitors. 

Set with precious 
stones, the "Jewelled 
Hare" was originally the 
subject of a book called 
"Masquerade" written 
by Kit Williams in 1979. 

It was the subject of 
an international treasure 
hunt undertaken by the 
book's readers around 
the world. 

For "Masquerade" 
contained all the clues 
to find the hare which 
had been sealed in an 
earthenware jar and 
buried in a secret 
location by the author 
and television per- 
sonality Bamber Gas- 
goigne. A man called 



treatment 



Ken Thomas finally 
solved all the clues and 
dug it up in 1 982. 

When buried, it was 
valued by the author at 
£5,000. Three years 
later, when it was 
unearthed, its estimated 
worth had soared to 
more than £20,000. 

Earlier this year, the 
precious item was 
bought by Haresoft Ltd. 
to launch a world-wide 
computer competition, 
with the hare as the 
prize. 

A team of six pro- 
grammers and two gra- 
phic designers has spent 
three months producing 
a find-the-treasure pro- 
gram, which they claim 



is not a game but a mind 
bending puzzle. 

To give an equal 
chance to youngsters 
who cannot travel freely, 
the hare has not been 
buried this time. All the 
winner will have to do is 
solve the clues con- 
tained in the program to 
pinpoint its exact 
location. 

Haresoft has pro- 
duced the program in 
two parts - each costing 
£8.95 - and they will be 
released three months 
apart. 

The first tape - 
Hareraiser Prelude - 
became available in the 
middle of June, with 
part two - Hareraiser 




Finale - due in mid- 
September. 

Both tapes will be 
needed to find the 
location of the treasure. 

To scupper the 
pirates the tapes include 
information that the 
average computer 
owner will not be able to- 
reproduce. Should 
copies be taken, the user 
will not be aware that all 
data is not present. 



from columns or other 
obstacles. 

Set in 200 acres of 
parkland overlooking 
London, the Palace has 
ample parking facilities. 

For those who want 
to leave their cars at 
home, the Palace can be 
reached easily by train. 

Average journey time 
from Piccadilly Circus is 
30 minutes. 

On the underground 
the Victoria Line 
provides fast access to 
and from the West End 
and British Rail mainline 
stations - King's Cross, 
St. Pancras, Euston and 
Victoria. 

Visitors travelling on 
the Victoria Line should 
change at Highbury and 
Islington for the BR 
suburban service. 

Alexandra Palace can 
be reached by the Pic- 
cadilly Line from Heath- 
row Airport, West End 
and King's Cross main- 
line station. 

The line serves Fins- 
bury Park and Wood 
Green underground 
stations, which are also 
linked to the Palace by 
the London Transport 
W3 bus service. These 
run every seven to ten 
minutes, seven days a 
week and extra buses 
will be provided during 
the show. 

The nearest station to 
Alexandra Palace is the 
British Rail Alexandra 
Palace on the main and 
suburban line from 
King's Cross and Moor- 
gate. 



PLUS 1 IS IN THE PIPELINE 



YOU may have to wait a 
little longer to get your 
hands on a Plus 1 , 
Acorn's long-awaited 
hardware expansion 
unit for the Electron. 

Dealers are reporting 
considerable delays in 
meeting the demand. 



But Tom Hohenberg, 
Acorn's marketing 
director, brushes aside 
suggestions that there 
are production snags. 

"We only launched 
the Plus 1 at the end of 
May", he told Electron 
User. "All the dis- 



tributors and major 
retail chains have 
ordered it, and 
thousands of Plus 1 s are 
now coming off the 
production lines". 

And he added that 
2,800 Plus 1s were 
ordered in advance of 



the launch. 

Meanwhile, a 
spokesman for W.H. 
Smith said they had 
placed an order for 
around 500 units - 
enough to put two in 
each of their computer 
shops. 



August 1984 ELECTRON USER 7 



Part six of PETE BIBBY's 
introduction to programming 



WE'LL be taking a further 
look here at the FOR... 
NEXT loops which we 
learnt about last time. First, 
however, let's recap on 
what we've covered in the 
first five articles in the 
series. 

We started on Page 10 of 
the February edition where we 
made the acquaintance of the 
PRINT command which we've 
been using to good effect ever 
since. 

We saw how we could use 
it to add two numbers together 
and also to get the Electron to 
say "Hello"' to us. 

We learnt that the Electron 
uses an asterisk * as the 
multiplication sign and the 
diagonal / as the division sign. 
All this was in command 
mode, the Electron responding 
immediately to whatever we 
typed in. 

Page 1 of the March issue 
took us into the world of 
simple programs. We saw that 
a computer program was a 
series of numbered commands 
which the Electron obeyed in 
order when we entered RUN. 
We found out how to LIST 
them and how to wipe them 
from the micro's memory by 
typing NEW. 

New lines could be added 
to programs by simply typing 
them in, while whole lines 
could be deleted by entering 
that particular line numberand 
pressing the Return key. 

We learnt the reason for 
numbering the lines in steps of 
1 - so we could slip new lines 
in between them. We also 
found out how to use the 
Delete key to alter program 
lines before we'd actually 
entered them into the Elec- 
tron's memory by pressing 
Return. 

Finally, we saw how CLS 
could be used to clear the 
screen. 

Not content with all this 
knowledge. Page 8 of the April 
issue saw us pressing on. We 
covered the REM statement, 
which allowed us to make 
remarks that the Electron 
ignored. 

We did a little more work 
with strings, combinations of 
letters and numbers that we 
put inside inverted commas 
and that the Electron treats as 





one lump. 

We added to our know- 
ledge of the PRINT command, 
seeing how the punctuation 
that follows it affects the 
screen display it produces. 

And it was this month that 
we learnt how to use the LET 
command to assign variable 
names to strings. 

Having dealt with that, it 
then turned out that we didn't 
need to use LET - the Electron 
assumed it was there anyway. 

Those who persevered until 
Page 1 of the May issue were 
rewarded with the secrets of 
assigning values to numeric 
variables. 

There was also a demon- 
stration of how to use numeric 
variables for simple maths. 
The concept of using mean- 
ingful variable names was 
raised and we "explored the 
rules that the Electron requires 
for variable names. 

Page 10 of the June issue 
introduced the very powerful 
INPUT statement, which is 
used to enter values into 
programs while they are 
actually running. 

We explored the way it 
works and saw how it is 
always wise to print a mes- 
sage explaining clearly which 
input a program requires. 

Finally July. Page 10, saw 
us going round in circles 
following the workings of 
simple FOR . .. NEXT loops. 

We explored the way that 
these loops and the INPUT 
statement combine as a 
powerful programming tool. 









and I left you with two 
problems. 

The first is shown by 
Program I, July's Program X. 
Why, I asked, was loop equal 
to 6 and not 5, as we might 
have expected? 



10 REH PR06RAH I 




20 REH OLD PROGRAM X 




30 FOR loop=l TO 5 




40 PRINTTass nuiber 1 


;loop 


50 NEXT loop 




60 PRINT "Final loop 


is "; 


loop 





The answer is that the 
NEXT statement adds one to 
the value of loop each time 
around and the Electron then 
compares this with the upper 
limit of the loop. 

This upper limit is the value 
that follows the TO in line 30. 
If the value is less than or 
equal to this limit (in this case 
if the value is 5 or less) the 
program goes round the loop 
again. 

So when the value of loop 
gets to 5, after having been 1, 
then 2, 3 and 4. the loop is 
repeated once more. Now 
when the program gets to the 
NEXT, loop is increased by one 
and so loop is equal to 6. 

The Electron then com- 
pares this value with the upper 
limit that has been set for the 
FOR . . . NEXT loop. In this 
case loop now has the value 6, 
while the upper limit of the 
loop is given as 5. 

Since this is the case the 
Electron knows that it has 



finished going round the loop 
and so it goes on to the 
following line, line 60, which 
prints out the unexpected 
value for loop. 

Work it out on a piece of 
paper if you can't follow that. 
It's one of those things that 
can be difficult to understand 
until you grasp it and then it's 
suddenly obvious and you 
can't see how you ever had 
any difficulty. 

In fact that could be said 
about most things in program- 
ming. 

Program II is a lot easier to 
sort out. 



10 REH PROGRAH II 




20 REH OLD PR06RAH XI 




30 FOR loop=5 TO 1 




40 PRINT "Sonething's 


Hrong 


here!" 




50 NEXT loop 





Here the limits that I've 
given to the loop are the wrong 
way round. There's no way 
that the loop variable loop can 
go from 5 to 1 in steps of one 
at a time. 

When the program enters 
the loop the value of loop was 
set to 5 by line 30. It then went 
on to line 40 which PRINTed 
out the message and line 50 
added one to the value of loop, 
which thus became 6. 

Since 6 is greater than the 
upper limit of the loop variable 
(which line 30 set to 1) the 
program stopped going round 
the loop and, since there are 
no other lines, it stopped 



8 ELECTRON USER August 1984 




completely. 

This may seem a stupid 
mistake but it can happen, 
especially when one or both of 
the limits of the loop control 
variable are given as variables 
rather than figures. 

Program III is an example of 
using a variable to control the 
limits of a loop. 



to define the limits of FOR . . . 
NEXT loops makes programs 
much more flexible. 

Now take a look at Program 
IV. 



10 REN PROGRAM III 

* 


20 INPUT "How fflany nuabers 


are there", hon^any 


30 totaH 


40 FOR locp=l TO hoHjuany 


50 INPUT "Enter nuaber'.n 


uaber 


40 total=total+nuiber 


70 NEXT loop 


80 PRINT "The total of the 


fl ;hoH_Bany; B numbers is 


"itotal 



10 REM PROGRAM IV 


20 FOR count= 1 TO 9 


30 PRINT count 


40 NEXT count 



Not exactly rivetting is it? 
All it does is produce a 
sequence of numbers from 1 
to 9. 

However suppose that you 
didn't want the series 1, 2, 3 
and so on to 9 but wanted only 
the odd numbers, 1, 3. 5 and 
so on. Can you do it with a 
FOR . . . NEXT loop? The 
answer is yes, as Program V 
shows. 



This is a modification of the 
July program which added 
together 10 numbers. There's 
no reason why it should be 
limited to only ten, it could be 
used to add together any 
number of numbers. 

This is achieved by using a 
variable how_many after the 
TO that defines the limits of 
the FOR . . . NEXT loop. 

Before the program reaches 
the loop it makes the Electron 
ask us how many numbers we 
are going to type in. 

It then gives this value to 
the variable how_many and 
this sets up the loop for that 
number of entries. Try it and 
you'll see how using variables 



10 REM PROGRAM V 


20 FOR count= 1 TO 9 STEP 2 


30 PRINT count 


40 NEXT count 



This prints out the required 
series, doing it by using the 
keyword STEP to modify the 
way that the loop control 
variable is increased. 

Up until now we've been 
used to FOR . . . KlEXT loops 
where the loop control vari- 
able is increased by one every 
time round the loop. 

However, as Program V 
showed, we're not stuck with 
this. By using STEP we can tell 
the Electron how much to 
increase the control variable 
by each time round the loop. 

In Program V the STEP was 



followed by the figure 2 and so 
the loop control variable count 
was increased by two every 
time around. 

The FOR . . . NEXT loop 
works in exactly the same way 
as before, repeating over and 
over until the loop control 
variable exceeds its upper 
limit. 

In fact you could say that 
our FOR . . . NEXT loops have 
always had a step factor, STEP 
1 . which the Electron assumes 
and so we haven't had to type 
it in. 

In Program V all that's 
different is that we wanted 
increments of two so we used 
STEP to achieve this. 

Try putting different num- 
bers after the STEP of line 20 
and see how it works in 
practice. Like most things in 
the world of micros, until 
you've done it for yourself it 
won't really sink in. 

The steps that the control 
variable is increased by don't 
have to be whole numbers, as 
Program VI shows. 



10 REM PROGRAM VI 


20 FOR count= 1 TO 9 STEP 

.5 
30 PRINT count 


40 NEXT count 



Here the increment is 
fractional, yet the loop still 
works in the normal manner. 
Again, try it out with your own 
fractional values after the 
STEP and see how count 
varies. 

As Program VII demon- 



strates, the step can even be 
negative. In this case the loop 
repeats until the final value of 
the loop variable count is less 
than the final limit of 1. 

Notice that the limits are 
from 9 to 1 . See what happens 
if you put the limits in the other 
way around, by mistake. 



'10 REM PR06RAM VII 

20 FOR count= 9 TO 1 STEP - 

1 


J 

30 PRINT count 
40 NEXT count 





So far the examples of the 
use of STEP have been fairly 
academic. Program VIII shows 
the use of STEP in a more 
realistic situation. It's the kind 
of use you'll find for it in your 
own programs. 



10 REM PROGRAM VIII 


20 MODE 2 


30 FOR line=0 TO 1279 STEP 


64 


40 HOVE line.O 


50 DRAW line, 1023 


60 NEXT line 



Here the value of step is 
chosen in order to space the 
lines. Try out different values 
and see the results. 

This is where the STEP 
facility comes into its own, 
allowing values to be in- 
creased or decreased by a 
specified amount each time 
round a loop. As you gain more 
programming experience 
you'll realise how useful it can 

be. 

And that's all for this 
month. Next time we'll be 
moving onto a new aspect of 
FOR . . . NEXT loops. For a 
preview take a look at Program 
IX. 



10 REM PR06RAM IX 

20 FOR outer=i TO 3 

30 PRINT "Outer loop nutber 

"; outer 
40 FOR inner=l TO 3 
50 PRINT "Inner loop ";inne 

r 
60 NEXT inner 
70 NEXT outer 



Loops within loops. Can you 
figure out what's happening? 

We'll go into it in the next 
article. 



. 



August 1984 ELECTRON USER 9 




SOONER or later when 
writing programs there is a 
need to generate a series of 
numbers, all different and 
in a random order. 

At first thought this would 
seem straightforward using 
the RND facility and Program I 
would seem to fit the bill: 



By DAVE ROBINSON 



10REM PROGRAM I 
20DIH nuaber(lO) 
30F0R 1=1 TO 10 
40nuiber(I)=RNDU0) 
50NEXT I 

60REH Print out nuabers s 
elected. 

70F0R 1=1 TO 10 
80PRINT nuiber(I) 
90NEXT I 



Unfortunately, if you run 
Program I, you will find that 
the RND function on line 40 
will quite happily choose the 



same number more than once 

- in the range of 1 to 10. 
What is needed is a check 

routine to stop this happening. 

Program II will do this 
checking. 

The FOR . . . NEXT loop - 
lines 90 to 1 1 - checks back 
through all the previous num- 
bers to see if the new number, 
from line 60 has been selected 
before. 

If it has. then the flag match 
is set to TRUE. The REPEAT . . . 
UNTIL loop - lines 60 to 1 20- 
is then repeated until a new 
number is found that has not 
been used before. 

The TIME variable - line 30 

- is set to zero to find the time 
the program takes to select 1 
random numbers, using the 
ro.utine in Program II. 



The actual time will vary 
each time the program is run 
depending on how many times 
the repeat loop is called. 
Typical times are around one 
second. 

This time is probably 
acceptable if only 1 numbers 
are needed. But if 1 00 or more 
are required, the time 
becomes quite long. 

It takes Program II nearly 
three minutes to do 100 
numbers - how can we 
improve this? 

One method would be to 
keep a record of each number 
used. This makes it possible to 
quickly check each new 
number chosen by the RND 



function against those 
previously stored. This saves 
doing comparisons against all 
previous numbers. 

Program III does this. 

This time a "used" array 
records whether or not a 
particular number has been 
chosen. 

It does this by being 
initialised to FALSE (the 
number 0} at the beginning of 
the program - lines 40 to 60 - 
and reset to TRUE (the number 

— 1) each time a random 
number is stored in the 
number array - line 10. 

The REPEAT... UNTIL loop 

- lines 80 to 1 00 - will check 
each subsequent random 
number chosen before allow- 
ing it to be added to the 
number array. 

The FOR ... NEXT loop - 



10REH PROGRAM II 


110NEXT J 


20DIH nuiberUO) 


120UNTIL iatch=FALSE 


30TME=0 


130NEXT I 


40nunber(l)=RND(10) 


140PRINT TIHE/100; "seconds 


50F0R 1=2 TO 10 


1 


60REPEAT 


150REM Print out nunbers s 


70natch=FALSE 


elected. 


80nu«ber(I)=RND(10) 


160F0R 1=1 TO 10 


90F0R J*l TO 1-1 


170PRINT nuiber(I) 


100IF ntiiber(I)=nu»ber(J) 


180NEXT I 


THEN Mtch=TRUE 







10REH PROGRAM III 




1301=0 


20DIH nunberUOO) 


,used(l 


140REPEAT 


00) 




1501=1+1 


30TIHE=0 




160UNTIL used(I)=FALSE 


40F0R 1=1 TO 100 




170niuber(100)=I 


50us6d(I)=FALSE 




. 180PRINT TIME/100; "seconds 


60NEXT I 




It 


70F0R 1=1 TO 99 




190REH Print out nunbers s 


80REPEAT 




elected. 


90nuaber(I)=RND(100) 
100UNTIL used(nu«ber(I))=F 

A 1 " ^ 


20067.=4 

210F0R 1=1 TO 100 


ALSE 
110used(nu«ber(I))= 
120NEXT I 


■TRUE 


220PRINT nuiber(I); 
230NEXT I 



Program II 



Program III 



10 ELECTRON USER August 1984 





lines 70 to 1 20 - is set to the 
total less one because the last 
number can only have one 
vafue, and it is more efficient 
to check through the "used" 
array to see which subscript is 
still FALSE rather than wait for 
the RNDfunction-line90-to 
find it. 

If you run Program III. you 
will find the speed has 
increased considerably. 100 
numbers taking around four 
seconds and 10 numbers 0.35 
seconds. 

I say around because the 
two repeat loops will be called 
a different number of times 
depending on the random 
numbers chosen. 

The variable Qi% on line 
200 is used to space out the 
numbers across the screen. 
See the User Guide for more 
details. 

You can see that the 
improvement in time for 10 
numbers is probably not worth 
the extra programming or 
memory used. For 100 num- 
bers or more it may be 
considered. 

Once on the pursuit of 
speed I realised that the one 
stumbling block was having 
any kind of check routine each 
time a new number is chosen 
by the RND function. What 
was needed was a method 
that made this checking 
unnecessary. 

Consider, for a moment, 
what a bingo caller does. He 
takes a number from a random 
generating machine calls it out 
and then puts it on a board. 

After this he takes another 
number from his machine - 
but now the machine does not 



contain the first number he 
took, so it cannot be called 
again. No need for any 
checking 

This is what we need, the 
facility for reducing the num- 
bers available for selection, 
after every time we choose 
one. 

Program IV was the first 
attempt: 



10REM PROGRAM IV 

20DIK nuaberUOO) .select 
(100) 

30TINE=0 

40F0R 1=1 TO 100 

50select(I)=I 

60NEXT I 

70F0R 1=100 TO 2 STEP-1 

80choose=RND(I) 

90nu«ber ( I ) =sel ect (choose 
) 

100select(choose)=select(I 
) 
110NEXT I 

120nu«ber<I)=selectU) 
130PRINT TIME/100; "seconds 

140REH Print out numbers s 
elected. 
1508X=4 

160FQR 1=1 TO 100 
170PRINT nuiber(I)i 
180NEXT I 



This time the numbers 
available for selection are first 
initialised into a select array - 
lines 40 to 60. The FOR . . . 
NEXT loop -lines 70 to 110- 
then transfers these numbers, 
in a random order, into the 



number array. 

The secret lies in reducing 
the maximum value of the 
RND function on line 80 each 
time the FOR . . . NEXT loop is 
called. 

This means that the vari- 
able choose can be any 
number between one and 1 00 
on the first pass; between one 
and 99 on the second pass and 
so on, down to between one 
and two on the last pass. 

So, if after the transfer has 
occurred — line 80 - we 
overwrite the contents of the 
select array, subscript number 
stored in choose, with the 
contents from the same select 
array but subscript stored in 
the loop counter 1 (100 on the 
first pass. 99 on the second 
pass etc.). 

This means that even if the 
variable choose was the same 
value in any subsequent pass, 
the contents of the select array 
being transferred would be 
different. 

The FOR . . . NEXT loop - 
lines 70 to 1 1 - stops at l=2 
because you must avoid let- 
ting c/?oose=RND(1). 

Otherwise choose would 
equal a decimal number less 
than one, and anyway there is 
only one number left in the 
select array. Line 120 trans- 
fers this to the number array. 

Further thought showed 
that this technique can be 
modified to use a single array 
for both selection and storage 
of numbers. This saves con- 
siderably on memory if a lot of 
random numbers are required. 

This is done by using a 
single variable, temp, to hold 
the chosen number while the 
transfer - line 1 1 0, Program V 
- takes place. The chosen 
number can then be put into 
the end of the array. Look at 



PROGRAM 


NUMBERS SELECTED 


10 


100 


1000 


II 
III 
IV 

V 
VI 


1-2sec 
.2-.3sec 
,17sec 
.13sec 
.1 1sec 


2-3min 
4-6sec 

1.62sec 
1.3sec 

1 .06sec 


1-1 .5min 

16.9sec 

13.1 5sec 

10.74sec 



lOREM PROGRAM V 

20DIH nunberXllOO) 

30TIHE=0 

40F0R IX=l TO 100 

50nu«berX(IX)=IX 

60NEXT II 

70F0R IWOO TO 2 STEP-l 

80choosrt«RND(II) 

90tefflpZ=rtu«ber7. (chocseX) 
lOOnunberZ(chooseX)=nu«ber 
7. (II) 
HOnuiberMD'tMpI 
120NEXT ll 
130PRINT TIME/lOOi "seconds 

140REM Print out nuibers s 
elected. 
150M=4 

160F0R IZ=l TO 100 
170PRINT nu«berX(IX); 
180NEXT IX 



Program V and you will notice 
that I've used integer variables 
with the % sign. This will by 
itself increase the speed of any 
program. 

If you wish to go to the 
limits of the machine 
efficiency, then the answer is 
to use single letter integer 
variables and put all of the 
program on one statement line 
separated by colons with no 
unnecessary spaces. 

See Program VI. The pro- 
gram is now difficult to read 
but essentially is the same as 
Program V. 



lOREM PROGRAM VI 
20TIHE=0 

30DIMNXU00) :F0RIX=lT0l00 
:NX(IX)=IX:NEXT:F0RIX=i00T02 

STEP-l:CX=RND(IX):TX=NX(CX): 
NX(CX)=NX<IX):NX(IX)=TX:NEXT 

40PRINT TIHE/I00; a seconds 

50REM Print out numbers s 
elected. 
&0§X=4 

70F0RIX=l TO 100 
80PRINT NX(IX); 
90NEXT IX 



Figure /: Running times 



• Program running times are 
shown in Figure I. 



August 1984 ELECTRON USER 1 1 




Notebook 



Part 7 



comes from 




Mrs S.M 



th e D RAW / n d f awv lines 

COmma „£ne° to «orm an 
that commno w 

Lmost so«d Pf «*»• 



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another pattern- __ 



Z./7?e No. 
10,20 

30 



40 
50,60 



70 

80 
90,160 



100 



110 



120 
130-150 



170 



KK. ■-- * a "s* i-fflSKSr 

graphics modes, 0,Z,« ° r 
? T,ttlec.ro n .0 clear the graphW area 

««&«« — 

foreground colour. )oop The 

These lines form a FOR - f 10 each 

sa s?ss jjks - » ■ -^ 

point. „ i; ne from 

The Electron now J; 1^.^ 

100 .100 to the pom, wh ^ ^ 

are top, 1 000. Each fay ^ , s 

the X t°Z This moves the point that 
SSdrUntoacrossthescreentothe 

3C the last pojnt ^Xr 
1 179,100 every time rouna 

These lines do the »™ >°^- ina tes. 
three did, only w.th d fferer ^ 

fere stfJ ^ - - 

the prompt. 




Q JJ REN LINES AND PATTERNS 

^20 REN BY S.N.PRICE 
_3_0 NODE 1 I 



Coh 



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OO066 screen to 

&£ right ~ 

Hoses bottom 

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screen to the 
right 



f 15 VDU 23,l l 0;0;0 i 0j 
50 WW 19,1,5,0| 

M VDU 1?,128,134;0; 
70 SCOL 0,128:CLS 
M SCOL 0,1 
90 FOR top=100 TO 1179 
STEP 10 
Q 100 NOVE 100,100 

—I 110 DRAW top, 1000 
q 120 DRAW 1179,100- •• 
130 NOVE 100,1000 
HO DRAW top, 100 
150 DRAW 1179,1000 
160 NEXT top 
.Q 170 REPEAT UNTIL FALSE ' 



Mode. 
Tec±z 




Endless 



I ress tscape 



I 





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JOHN 
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shows how 
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THIS article explains the 
development of a routine 
to make any computer 
character appear as large as 
the screen. The routine will 
allow the height of the 
characters to be 8, 1 6, 24 or 
32 screen lines high. 

I was first given the 
incentive to solve the problem 
when a colleague attempted 
to draw (PLOT) a series of 
numbers. 

Each number had to be read 
from a standard TV screen by 
pupils at the back of a large 
classroom and had to be at 
least eight screen lines or 256 
points high. 

To design each character 
individually using PLOT state- 
ments took as long as the 
development of this single 
routine that will generate all 
computer characters. 

The short cut to creating 
giant letters is to use the 
actual shapes of the character 
matrices stored in ROM and 
magnify them. 

Each character is stored 
and displayed as a 8 x 8 matrix 
of dots. The shapes of the 
standard characters are stored 
as eight bytes, one for each 
row. 

For example the letter A is 
shown in Figure I. 




The characters can be 
changed or produced using 
VDU 23. For example, charac- 
ter 65 can be changed using: 

VDU 23,65,16,56,108, 
68,124,198,i30,0 

(See Pages 109 and 110 of 
the Electron user guide.) 

You can find out the actual 
shape of a character stored in 
ROM by counting the dots on 
the screen. But the Electron 
has a much better and faster 
method. 

Using the OSWORD CALL 
(A%-10) reads the matrix of a 
character and places it in RAM 
at a location specified by the 
values stored in X% and Y%. 

For example the routine: 

0Sy0RD=lFFFi:AI=10:XX470 
:YX=iO:?i70=ASCCA 1 

.•CALL OSWORD 




1 

2 6 3 1 






8 4 2 6 8 4 2 


1 




--lift- 


- 32+16+8+4 


60 (&3C) 


9 V ~~ 9 9 


- 64+32+4+2 


102 (&66) 


9 9 9 9 


- 64+32+4+2 


102 (8.66) 


- •••••• 


- 64+32+16+8+4+2 


126 (&7E) 


9 9 


- 64+32+4+2 


102 (8.66) 


9 9 — 9 9 


- 64+32+4+2 


102 (&66) 


9 9 9 9 


- 64+32+4+2 


102 (&66) 
(&0) 







Figure I: The character A 



Figure II: Character locations 

places the eight matrix values 
of the character A in the 
locations &71 through to 
8.78, 

Note that the character to 
be analysed is placed in 
location 8(70. That particular 
area of RAM was chosen 
because it is safe for machine 
code programs. {See the user 
guide. Page 214.) 

The contents of those 
locations can be examined 
using the instruction PRINT 
?&71 or PRINT ?8<72 etc. 

The results shown in Figure 
II should be obtained, provid- 
ing that the shape of A has not 
been changed. 

These values can now be 
used to construct the large, 
character shapes. This can be 
done in Basic chr%-l&l\ or 
i n asse mbly language 
LDA&71:STAc/w% 

The next problem is to 
translate each byte of the 
matrix into a line of eight 
characters. Looking at the 
letter A, the first value (?&71 ) 
is 60 and must be translated 
into this line of characters: 
space space blob blob blob 
blob space space 

What should the blobs be? 
The easiest move is to define 



CHRS255 to be the blob using 
VDU23. 

VDU23, 255,255, 255, 255, 

255,255,255,255,255 

gives a solid square blob 
whereas: 

VDU 23,255,85,170,85, 
170,85,170,85,170 

gives a shaded blob. 

We must now turn to 
exponentials and Boolean 
logic - but don't despair, it's 
not that bad ! - to discover the 
relationship between the row 
numbers and the pattern of 
blobs. This is shown in Figure 
III. 

A routine in Basic that will 
determine whether it should 
be a blob or a space by 
examining the binary structure 
of the number is shown in 
Program I. 

Please note that this is not 
the simplest way to produce 
this result but it shows clearly 
the steps that have to be taken 
to get from the number to the 
row of spaces (CHR$32) and 
blobs (CHR$255). 

It would be better to use 
VDU instead of the PRINT 
CHR$ and ;. 

The AND operator com- 



18 ELECTRON USER August 1984 



pares the variable, or constant, 
on the left hand side with the 



IOREM PROGRAM I 
20VDU23,255,255,255,255,2 

ec «erc; ■>« ice *>« 

30REPEAT 

40INPUTnusber% 

50VDU11 

iOIF(2'7ANDnui8ber7.!THENPR 
INTCHR*255;ELSEPRINTCHR*32; 

70IF (2 A 6ANDnu»ber7J THENPR 
INTCHR*255;EL3EPRINTCHRt32: 

80IF(2 A 5ANDnunberZ) THENPR 
INTCHR*255;EL3EPRINTCHR*32s 

?0IF(2 A 4ANDnu«berX) THENPR 
INTCHRt255;ELSEPRINTCHRJ32; 

!00IF!2 A 3ANDnu«berX! THENPR 
INTCHR*255;ELSEPRINTCHR$32; 

110IF(2 A 2ANDnuiberX)THENPR 
INTCHR*255;EISEPRINTCHR$32; 

120IF(2 A lANDnu«berX)THENPR 

I NTCHR*2S5 ; ELSEPR I NTCHR*32; 

130IF(2 A 0ANDnu»berZ! THENPR 
INTCHR$255;ELSEPRINTCHR$32s 
140PRINT;nuiiberX 
150UNTIL FALSE 



Program I 



m 



mm 



variable, or constant, on the 
right hand side. That com- 
parison is made in binary. 

For example, the statement 
PRINT 53 AND 1 05 will 
produce 33 ! 

53 = 1 1 1 1 
105 = 01101001 
AND 1 1 =33 
With AND the answer has a 
1 if both the first number AND 
the second number has a 1 . If 
either number is zero or both 
are zero then the result is zero. 
Each bit of the eight bit 
number is considered separ- 
ately. In our program above 
number% is compared with 
these numbers in turn: 

2a7 = 128 = 10000000 
2a6 = 64 = 01000000 
2a5 = 32 = 00100000 
2a4 = 16 = 00010000 
2a3 = 8 = 00001000 
2a2 = 4= 00000100 
2a 1 = 2 = 00000010 
2a0 = 1 = 00000001 

If number% has a 1 in the 
same position as the 2a7 then 
the result is greater than zero 
and a blob is printed. If it has 
not then the result is zero and a 
space is printed. 

To simplify the program a 



60 is equal to 
60 in binary is 



space space 


0x2^7 0x2^6 
0+0 



blob 

1 

1x2^5 

32 



blob 

1 

1x2^4 

16 



■n^l^HHV ^1 




IOREM PROGRAM III 


■■ 1 

^^^^■"TB ft 


20REPEAT: PR0C1 gep (0 , .GET 


,1):UHTILFALSE 




30DEFPR0C1 gep J ht abX , vtabl 




,chrZ,sizeZI 


■ fllfl ■ 


40L0CALpo5Z,vposZ,acro5sZ 




,down v l .ffiaqI':,maq2'/.,;i!od8':,arr 

art 

50vposy.=VP0S:posX=P0S:err 






or**" 




60VDU23,255,255,255,255,2 




55,255,255,255,255 




70PRINTTAB(0,0)'TAB(7?}; 




80 1 FP0S=79THEN«ode%=80 


Ah * K 


90IFP0S=39THEN«odeX=40 


mk 


1 00 IFPQS= 1 9THENmodeX=20 




liOIFsueKlORsizeZMTHENe 




rrorf="sizeX out of ranqe" 




120IF(si:eZ*B)+htabZ>MdeZ 




TrlENerror$= fl 5hape too far ri 




ght" 




130IF<sizeX*8)+vtabZ>32THE 




Nerror$= B shape too low down" 




140IFchrZ<320R(chrZM27AMD 




chr'/.<224)THENerror$= ,l chrZ ou 


loop can be used. See Program 


t of permitted range" 


II. 




l50IFerror$0 ,H THENPRINTTA 
8(0,Q)"ERR0R! "+errort:STOP 
160?«t70=chrZ: AX=10: XX=170: 

YX=0:CALUcFFFl 

170F0Rdo*nX=0TQ7 

180F0RftagiX=lT05izeX 

190PRINTTAB(htab*,vtabX+5i 

zeZtdonnZ+inagiZ); 
200FQRacrossZ=7T00STEP-l 
210F0R«ag2X=lT0si:eZ 
220IF2 A across?.AND?(&7i+doK 

nX) THENVDU2SSELSEVDU32 
230NEXT:NEXT:NEXT:NEXT 

240PR INTTAB (pasX , vpasX) 5 

250ENDPR0C 


iOREM PROGRAM II 1 
20VDU23 , 255 . 255 . 255 . 255 , 2 

35,255,255,255,255 

30REPEAT 

40INPUTi>MberX 

50VDU11 

SOFORacrossWTOOSTEP-1 
70IF(2 A acro5sXANDnusiberX! 

THENVDU25SEL SEVDU32 

SONEUacrossX 
90PRINT! number* 
100UNTIL FALSE 




Program II 




We are now in a position to 


Program III 



following this algorithm: 
1 : Store the variables neces- 
sary: 

character to be printed 
horizontal TAB position 
vertical TAB position 
At a later stage a magnifi- 
cation factor will be used. 
2: Record POS and VPOS of 
cursor. 

3: Use OSWORD A%=10 to 
determine the matrix of the 
character to be printed. 



blob blob 

1 1 

1x2^3 1x2^2 

8 + 4 



space space 



0x2^1 0x2^0 

+ 



=60 



4: Use nested loops to analyse 
and print blobs of the charac- 
ter. 
5. Reset cursor position. 

The procedure is contained 
in Program III. 

The following points should 
be noted: 

Line 40 defines all LOCAL 
values. This is most important 
if the procedure is to be 
treated as a utility and 
incorporated into a range of 
programs. It prevents double 
use of a variable. 

Line 60 sets CHRS255 to 
be a square solid blob. 
However any standard charac- 



Figure III: How 60 defines a row 



August 1984 ELECTRON USER 19 



From Page 19 

ter or defined character can be 
used by changing line 220. For 
example: 

220IF2 A acrossX AND 
?(Sc7l+downX) THEN 
VDUtZ ELSE VDU32 

produces # signs instead of 
square blobs. An interesting 
development is to replace 255 
with chr%. This makes the 
blobs the same as the large 
shape being printed. (If a letter 
F was being printed it would 
be made up of Fs.) 

To generate the a sign 
press the cursor left key with 
the shift pressed down. 

Lines 70 to 150 are not 
necessary for the successful 
running of the procedure. 
However they have two func- 
tions. 

They prevent unexpected or 
unwanted displays and 
therefore help to diagnose 
programming errors. They also 
serve to illustrate the function 
of the four variables passed to 
the procedure. 

Lines 70 to 100 determine 



10REH PROGRAM IV 
20REPEAT:PR0Clgep(0,Q.6ET 
,1):UNT1LFALSE 

30DEFPR0Clgep (htab£, vtabZ 

,chrX f 5i2eX):L0CALposX,vposX 

,acrossX ! downX,sagl7.,aag2:;:v 

pcs%=VP0S:posX=P0S:VDU23,255 

,255,255,255,255,255,255,255 
f 255:?*70=chrX:AZ=10:)lI=l70: 
YZ-0:CALL&FFF1 

40F0Rdown2=0T07:F0RaaqlX= 
!TQsi2e%:PRINTTAB(htabZ,vtab 
?.+si:e?.*doHnX+flaglZ);:FQRacr 
QS5?.=?T00STEP-i:FQR«aq2?:=tT0 
si:e%:IF2"across%AND?(S:71+do 

mZ) THENVDU2S5ELSEVDU3Z 

50NEXT,,,:PRINTTAB(pos7.,v 

posZM:EN0PR0C 



Program IV 

the number of characters per 
line. The variable mode% holds 
that number. 

The size% variable must not 
be greater than 4 because the 
enlargement would be too 
great and overfill the screen. 

The range of valid chr% 
must be set to prevent 



OSWORD being called to 
characters not held in RAM. If 
the number of redefinable 
characters has been increased 
by exploding the memory (see 
Pages 93. 94. 95 and 282 of 
the user guide) the range set 
on line 140 must be changed. 

The final line of the error 
trapping section stops the 
program if an error exists. This 
whole section is only useful in 
the program development 
stage. 

Lines 70 to 150 should be 
removed to save memory and 
reduce loading time in the final 
version of a program. 

The OSWORD call A%=T0 
on line 160 is explained on 
Pages 240-242 of the user 
guide. 

Finally line 240 returns the 
cursor to its original position 
before the procedure was 
entered. 

Program IV shows the 
minimum code required to 
write the procedure in Basic. 

Now try to make the 
procedure do some work for 
you. 

For instance, to print EU at 
the top left hand side of the 



screen type: 

PROClgepIO, 0,69,1 

PROClgep 10,0,85,1) 

Then Return. 

To clear a letter after 
printing it use: 

PROClgepIO, 0,32,1) 

(Note: The ASC of a blank 
space is 32.) 

Finally, to print every pos- 
sible character in turn use the 
procedure with this short 
program. Remember, you 
have to press the space bar to 
expose each letter. 



1 REM PROGRAM V 


2 FOR k=33 TO 126 


3 PROClgepIO, 0,32.1! 


4 PROClgepIO, 0,k,l) 


5 REPEAT:UNTIL 6ET=32 


h NEXT k 


7 END 



Program V 

Don't forget, the displays 
are not as good in the text 
modes (Mode 3 and Mode 6) 
as in the graphic modes. 

Now no one need say they 
cannot see the writing! 



GET LOST 

IN AN EPIC ADVENTURE! 

JOIN THE GROWING RANKS OF ADVENTURERS WHO REGARO OUR GAMES AS THE ULTIMATE ELECTRON ADVENTURES 



"Having now tried all of the Epic adventures they must be the yardstick by which all future adventures for the Electron should be judged" - Electron User. 

Sophisticated compression techniques allow us to pack approx. 230 locations and an average of 25 thousand characters of text into each game. 

CASTLE FRANKENSTEIN: The Frankenstein Monster was thought to have been killed in a fire at the Castle 20_years ago. but a series of unsolved 

murders has taken place and the people fear that the Monster is on the loose again. Explore the graveyard and Castle ruins, with its secret passages. 

sulphur pits, etc., to find and destroy the Monster. - C7.95 

"This, I feel, is the proper way to write an adventure". 

"One of the best all-round adventures I have ever seen for the Electron" Electron User. 

THE QUEST FOR THE HOLY GRAIL: To become a knight of the round table you must find the Holy Grail and return with it to Camelot. Your search will 

lake you through forest, swamp, castle, dungeons and rivers, and on the way you will meet many characters, some friendly some hostile. Can you outwit 

them all and solve the many puzzles to successfully complete your quest? - £7.95 

"Yet another superb adventure from Epic". 

"The puzzles are superb and I think praise is due to the program's writer" - Electron User. 

THE KINGDOM OF KLEIN: The Wicked Witch has stolen the Magic Klein Bottle from its pedestal in the palace. She swore that she would put a hideous 

curse on anybody who was foolish enough to try to recover it. Your task is to defy the Witch's curse and solve the mystical properties of the 5 solids, in order 

to kill the Witch and return the Bottle to the Klein Kingdom. - £7.95 

"Overall, a definite must for the experienced adventurer". 

"An extremely good adventure and excellent value for money. Recommended" - Electron User. 

THE WHEEL OF FORTUNE: Whilst walking along a lane you notice the Wheel of Fortune lying on the ground. On spinning it you find yourself in a 
strange and mysterious world, but the Wheel is gone. How can you return to civilisation without it ? Perhaps the beggar knows something, or the 
policeman. These are just 2 of the intelligent characters that you will meet in your adventure. 
This game contains a unique multi-statement language interpreter, intelligent characters acting in real-time, and a number of other advanced features too 

numerous to mention here. - £9.95 

"This is an exciting new adventure with some novel features". 

"The definitive Electron adventure. Highly recommended" - Electron User. 

Please make cheques payable to EPIC SOFTWARE and state clearly whether BBC or Electron versions are required. P&P FREE if ordering 2 or more 

games, otherwise add 50p. 



EPIC SOFTWARE 

Dept E, 10 Gladstone Street, Kibworth Beauchamp, Leicester LE8 0HL 

A II our programs are available for immediate despatch — Help service a vailable — Dealer enquiries we/come 



20 ELECTRON USER August 1984 



SOUND 




BUILD up a library of exciting sounds 

to enhance your own programs with 
these listings. And many more in the 
months to come! 





CPHQAg 



From James Harvey. 
Nottingham 

10 REPEAT 
20 FOB 1=1 70 5 
30 SOUND 1,-15,200,1 
« SOUND 1,-15,180,1 
50 NEXT I 

60 SOUND 1,-15,180,1 
70 FOR 1=1 TO 6 

80 SOUND 1,-15,200,1 
?0 SOUND 1,-15,180,1 
100 NEXT I 

HO SOUND 1,0,0,30 
120 UNTIL FALSE 



Do you have any sounds for Sounds 
Exciting? Send them into Electron User 
and hear yourself in print. The address: 
Sounds Exciting, Electron User, Europe 
House, 68 Chester Road, Hazel Grove, 
Stockport SK7 5NY. 



August 1984 ELECTRON USER 21 




S^sLS^SSS 



nptjorWjrfc fo Ce^j 





Everything 
on this page 
is 5% less 
than our 

normaf price 

This special 
offer is 

exclusively for 
readers of 
Electron User 
and applies to 
mail order 
sales only. 




We will also send you 
FREE membership of 
NMC's Computer Club - 
enabling you to enjoy 
generous discounts on all 
your future purchases! 

Benefits for Club members 
include a big saving of 
10% on software and 5% 
on hardware purchases 
over £25. 



Personal shoppers are 
welcome at our retail stores: 

National Micro Centres, 
36 St. Petersgate, 
Stockport SK7 5NY. 
Tel: 061-429 8080 

Wilmslow Micro Centre, 
62 Grove Street, 
Wilmslow, Cheshire. 
Tel: 0625 530891 



PRINTERS 

Now you can add a printer to your Electron, 
using Plus 1, we have selected four of the most 
popular dot-matrix printers. All allow you to 
condense or embolden text, offer high definition 
characters and allow you to produce clear-cut 
graphics and charts: 

Brother HR5(30cps) £170.95 

Brother EP22 £170.00 

Epson RX80(100cps) £272.00 

Epson RX80FT(incl. friction feed) £315.00 

For superb correspondence-quality printing you 
need a daisywheel printer. Our choice is one of 
our best-sellers, the Silver Reed EX43. It can also 
be used as a superior standalone electronic 

typewriter £394.25 

(Without Electron interface: £286.90) 



DATA RECORDER 

From a wide selection of cassette 
recorders we recommend the Pye 
Data Cassette Recorder, which is 
a perfect match for the Electron. 
With it comes a FREE power 
pack and Electron lead. 

£38.00 



MONITORS 

You can happily operate your Electron with your 
domestic TV set. But more and more users are 
finding that for a really crisp picture you need a 
special monitor. We offer a monochrome and 
three colour monitors: 

Zenith 12" (green screen) £81,00 

Microvitec (14" colour- low res) £217.41 

Microvitec ( 14" colour - med res) £326.66 

Microvitec (14" colour- hi res) £480.70 



For the best of both worlds there is the 14" 
Nordmende, which can double as a monitor and 

normal TV, at a very attractive price £238.00 

(with remote control £251.00 



V 



A FREE dust cover 
with every Electron 

We have ample stocks of Electrons and can promise 
mainland delivery within 24 hours of receiving your order. 
With it comes an introductory cassette of 15 programs, a 
very comprehensive User Guide, an easy-to-understand 
DIY book on programming AND a free dust cover 
with the compliments of 
National Micro Centres £189.00 

Electron Dust Cover if supplied separately £2.80 




JOYSTICKS 

Use a joystick to play arcade games and 
watch your score increase dramatically! 
For serious games a joystick really is a 
must - and we have two we specially 
recommend. Both provide twin fire 
buttons. 

Sureshot (self-centering action) ..£15.67 
Kempston £12.83 




Selling well . . . First Byte's 
switched joystick interface 

Since it was launched at the Electron & BBC 
Micro User Show the switched joystick interface 
from First Byte has been one of our top sellers. 
This plug-in cartridge takes standard Atari-style 
joysticks which are much more popular - 
and cheaper- than 
analoguejoysticks £23.70 



22 ELECTRON USER August 1984 



MAIL ORDER DIVISION 



Phone 
your order 



061-429 8080 



Answering service outside normal office hours 
Or use the order form below 



m 



AT LAST! Plus 1 

is the Electron 

add-on we've all 

been waiting for! 



ELECTRON PLUS 1 is Acorns answer to a 
growing demand from Electron users to be able 
to extend their micro's capabilities. With it you 
can add a printer and use your Electron for word 
processing and financial calculations. Its joystick 
input is designed to take two fully-proportioned 
joysticks - giving an entirely new dimension to 
games playing. And its two unique cartridge slots 
enable you to plug in games, educational and 
business programs - and that means no more 
waiting for programs to load. Many other 
manufacturers are now planning cartridges that 
will use Plus 1 to expand the Electron in many 
more exciting ways and considerably increase its 
power and versatility. 



Oar Top Ten 
Best Sellers 




ELECTRON PLUS 1 is a must for every user 
who wants to really make the most of his micro. 



Incredible 
value at 



£56.90 



Birds of Prey (Romik) 

A fast moving invaders type 
game where the aliens in space 
take the form of birds. Great 
value formoney £6.99 

Pharoah's Tomb (A & F) 

Seek the golden mask in this 
graphic adventure, solve 
anagrams and number puzzles 
- but avoid the monsters. 

£7.15 

Killer Gorilla (Micropower) 

Fast becoming a cult game. 
Dodge tumbling barrels and 
blazing fireballs. Gripping 
multi-level action £7.95 

Twin Kingdom Valley 
(Bug-Byte) 

A sophisticated adventure 
game with all 175 locations 
drawn in full-screen hires 
graphics £8.55 

Cylon Attack (A & F) 

"Outstanding . . . quite simply 
excellent ... the graphics leave 
most other games standing". - 
BectronUser £7.15 



Chess (Acorn soft) 
One of the best computer 
versions of the game, easy to 
use, with more options than its 
competitors £8.28 

Felix in the Factory 
(Micro Power) 

Never a dull moment for Felix, 
left in charge of the factory one 
evening. A great fun program. 

£7.15 

Snapper (Acornsoft) 

Gobble dots and fruit as you're 
chased round the maze by 
bog-eyed meanies. A real 
classic £8.28 

Starship Command 
(Acornsoft) 

Guide your craft through deep 
space and avoid an enemy 
bent on your destruction. Very 
addictive £8.28 

Chuckie Egg (A & F) 

A progressive game requiring 
extremely high skill levels. The 
nightmare has begun! £7.90 



ROM 
CARTRIDGES 

With Plus 1 you can use 
software cartridges on your 
Electron for the first time. 
Acornsoft has produced an 
initial range of cartridge 
games, educational and 
computer language 
programs, and many more 
will follow. 



ORDER FORM 



Post to: 

NATIONAL MICRO CENTRES, 
36 St. Petersgate, 
Stockport SKI 1HL 



DELIVERY CHARGES 

Hardware: £7 per item 
Software: FREE 



ALL PRICES GIVEN HERE 
INCLUDE VAT 



Item 



Please supply the following: 



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□ Cheque payable to 
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Signed 



EU11 



August 1984 ELECTRON USER 23 






PARACHUTE ! 






/ 





HAVE you ever wondered 
about the stories behind 
computer games? I mean, 
why are the aliens invad- 
ing? And why is the gorilla 
so mad? What's it all 
about? 

It's the same with A.G. 
MARTIN'S game, Parachute. 
For reasons best known to 
themselves, a group of sky- 
divers are hurling themselves 
out of a helicopter. Why? 

Your job is to catch them on 
your raft before they perish in 
the water below. 

The trouble is that your raft 
can only hold one person 
besides yourself, so every time 
you catch one you have to take 
him to one of the jetties to 
unload him. 

You score points for every 
man you catch, but when 
you've missed five the game's 
over. 

It's simple and it's fun to 
play. The instructions are in 
the game, now it's all up to 
you. Save the skydivers! 



24 ELECTRON USER August 1 984 



PROCboat 
PROCjump 

PROCcheck 

PROCscore 

PROCwaves 
PROCrun 



PROCEDURES 

Moves the boat. 

sk e y' d e ive, a rand ° m d "PP-ng eone for the 
bv h :he S r aft See if a ***" - been caught 

Se S ^y V --n a ^ eraftwhenft 



VARIABLES 

* ,u« Waves. 

^ 1$ ' W E',^SW3$ Waves. 

Li 



CO 

DIB, CDIR 

XINC, VINC 
IP 

xp, oxp 

C1.C2, C3 
COL 

JL $, JR$- L$ 
XF 



Lives lost. 
Lives saved- 

Colour of parachute. 
Position of ran- 

Mode. 

or sea). 

JeU,eS ' v,here parachute WW ^ nd " 
positior ^^^^^^^^— 



^ 



Parachute listing 



10 REM PARACHUTE 160 VDU23, 1 ,0;0;0;0; 

20 REN BY A.S.HARTIN 170 IP(1)=1:IP(2)=1:IP(3)=1 

30 REM (0 ELECTRON USER 180 VDU23, 202, 15,29,61,47,63 

40 DIM IP(4),C(4),)(F(4),XIN ,63,27,11 
C(4),YINC(4),X(4),Y(4),0]<(4),0 190 VDU23.204, 1 , 1 ,3,31 ,51 , 99 

Y(4) ,67,195 

50 H0DE6 200 VDU23.205, 128, 128,255,25 

60 PRINTTABI14, 2) "Parachute 5,254,12,8,8 

210 VDU23,206,255,127,63,31, 

70 PRINTTAB (14,3) -========= 16,56,56,0 

220 VDU23,207,8,8,B,252,4,6, 

80 PRINTTAB (14,6) ■CONTROLS' 6,0 

;TAB(13,7)" ■ 230 VDU23,208,48,48,240,240, 

90 PRINTTABI14,9)"Z=LEFT";T 0,0,0,0 
ABI14,11)"/=RI6HT" 240 VDU23.209, 0,0, 0,0, 12,28, 

100 PRINTTAB(10,13)"Y0U HAVE 60,60 
5 LIVES" 250 VDU23, 210,0, 0,0, 0,0, 240, 

110 INPUT TAB(14,18)"FAST/SL 240,240 
OK 1 , SPEED* 260 VDU23, 211, 240, 240, 240,0, 

120 IFSPEED$="FAST'io=5:Cl=l 0,0,0,0 
■60T0150 270 VDU23,212,0,0,0,0,0,0,25 

130 IFSPEED»="SL0H"iO=2:Cl=6 5,255 
:60T0150 280 VDU23,213,0,0,0,60,36,36 

140 PRINTTABI0,19)STRIN6$(11 ,36,126 
," *):S0T090 290 VDU23,214,60,60,60,60,60 

150 HODEio ,60,60,60 



H/£ 



'& 



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300 VDU23,215,0,0,0,0,24,24, 
24,0 

310 VDU23,216,0,0,0,96,96,96 
,0,0 

320 VDU23, 218, 0,0, 0,126, 255, 

226,60,0 

330 VDU23, 219,0, 0,0, 126,255, 
126,60,0 

340 VDU23 , 220 , 31 , 3 1 , 63 , 63 , 1 2 
7,127,255,255 

350 VDU23, 221, 20, 129, 0,129,0 
,20,28,28 

360 VDU23,222,24,60,60,24,8, 
24,56,56 

370 VDU23,223,32,57,79,207,2 

52,252,104,40 

380 VDU23, 224, 0,0, 0,0, 0,0,0, 
254 







,0 



390 VDU23, 225, 0,0, 0,0, 0,2,0, 

400 VDU23,226,0,0,0,0,48,0,0 

I 

410 VDU23, 227,2, 0,7,2,2,2, 5, 



420 VDU23 , 228 , 255 , 255 , 255 , 25 

5,255,255,255,255 

430 VDU23,229,20,B5,65,8,0,0 

,0,0 
440 VDU23,230,42,42,34,0,28, 

8,20,20 
450 VDU23, 23 1,255, 255, 254, 25 

4,252,252,248,248 

460 JL$=CHR$228+CHRf228+CHR$ 
228+CHR*228+CHR*228+CHR*231 : JR 
*=CHR*228 



August 1984 ELECTRON USER 25 



Parachute listing 



From Page 25 

470 P$=" "+CHR*10+CHR*8+CHR 
*8+' '+CHRI230 

480 Ml$=CHRf226:M2$=Nlf+" '+ 
W1*:H3*=H2*+" ■♦111 

490 SWlf=CHR$22S:SW2$=5Hl*+ B 
■+S«1$:SH3*=S«2*+" '+SH1* 

500 6C0L0,2sVDU19,2,0;0; 

510 N0VE0,250:DRAN400,500:DR 
AN400,575:DRAW,575 

520 6C0L0,2:F0RI=254T0 574ST 
EP4:PL0T77,0,I:NEXT 

530 H0VE1283,525:DRAN950,525 
: DRAW950 , 560 : DRfiWl 283 , 560 

540 FORI =526T0558STEP4 : PL0T7 
7,1000,I:HEXT 

550 VDU19,4,0j0; 

560 SC0L0.4 

570 F0RI=0T0550STEP4: PL0T77 , 
600, 1 « KIT 

580 GCOLO, CI 

590 VDU19,C1,0;0; 

600 F0RJ=554 T01100STEP4;PLO 
T77,600,J:NEXT 

610 VDU19,2,2i0;:VDU19,4,4i0 
;:VDU19,C1,6;0; 

620 GC0L0 , 0: HOVEO . 575: DRAHO , 
585:DRAM100,585:DRAM100,575:DR 
AMI 00 , 585: DRAN200 , 585: DRAW200 , 
575 : DRAW200 , 580 : DRAW300 , 580 : DR 
AU300, 575: DRAH300 , 580: DRAM390 , 
580:DRAN390,575 

630 IFn>5 C2=2 

640 IFio=2 C2=ll 

650 6C0L0,C2:H0VE970,656:VDU 

5 215 

660 6C0L0,7:N0VE970,656:VDU 
213 

670 H0VE97O,624:VDU 214 

680 N0VE970,592:VDU 214 

690 GC0L0 , 0: H0VE955 , 560: DRAW 
955,565:0RAH1055,565:DRAW1055, 
560:DRAN1055,565:DRAN1155,565: 
DRAW1 1 55 . 560: DRAW 1155, 565 : DRAW 
1255,565:DRAW1255,560:DRAH1255 
,565:DRAH1283,565 

700 GCOLO, 11:H0VE200, 918: VDU 
216 

710 GCOLO , 0: M0VE200 , 950 : VDU 
209,210:N0VE264,918:VDU 211 

720 IFio=5C3=3 

730 IF«o=2C3=9 

740 GCOLO, C3.-H0VE200, 982: VDU 
212,212 

750 6C0L0 ,7: H0VE200 , 950: VDU 
204,205,208:H0VE200,918:VDU 20 
6,207 

760 H0VE700,800:VDU5 223 



770 GCOLO , C3: H0VE700 , 832: VDU 

224 

780 VDU4: C0L0UR132: C0L0UR1 :P 

RINTTAB(10,25)CHR$220:C0L0UR12 
9 : C0L0UR7 : PR I NTTAB ( 1 1 , 25) CHR*2 

27 

790 VDU23,200,16,16,16,0,0,0 
,0,0 

800 L$=CHR*200+CHR*200+CHR$2 
00+CHRt200+CHR*200+CHR*200 

810 C0L0UR132:C0L0UR1:PRINTT 
AB (0 , 25) JL$; TAB( 19 ,25) JR*; TAB ( 
, 26 ) L« ; TAB ( 1 9 , 26 ) CKRS200 

820 XP=10:0XP=10:MAN=0 

830 LI=0:C0=0:HC=4 

840 VDU4:VDU23,1,0;0;0;0;:C0 
L0UR2:PRINTTAB(0, 30) "LIVES ";L 
IiTAB110,30)"SAVED ";CQ 

850 PROCboat 

860 HN0=RND(2):IFWN0M PROCm 
aves 

870 PROCjuip(l) 

880 IFLI=5 PR0Cscore:G0T0830 

890 PROCboat 

900 PR0Cjuap(2) 

910 IFLI=5 PR0Cscore:G0T0830 

920 PROCboat 

930 PR0Cju§p(3) 

940 IFLI=5 PR0Cscore:G0T0830 

950 PROCboat 

960 PR0Cju«p(4) 

970 IFLI=5 PR0Cscore:G0T0830 

980 G0T0850 
990 END 

1000 : 

1010 DEFPROCboat 

1020 IFINKEY<-98)XP=XP-1:G0T0 

1050 
1030 IFINKEY(-105)XP=XP+1:G0T 

01050 

1040 G0T01110 

1050 VDU4 : C0L0UR1 32 : C0L0UR4: P 
RINTTAB(0XP,25)" " 

1060 IFXP<6 XP=6 

1070 IFXPM7 XP=17 

1080 C0L0UR132: C0L0UR1 : PRINTT 
AB(XP,25)CHR$220:C0L0UR129:C0L 
0UR7:PRINTTAB(XP+1,25)CHR$227 

1090 IFXP=6 PROCrun 

1100 IFXP=17 PROCrun 

1110 IF MAN>0 GCOLO, HAN:H0VEX 
P*64,220:VDU5 227 

1120 0XP=XP 

1130 ENDPROC 

1140 : 

1150 DEFPROCjmp(N) 



1160 C0L=C1:IFIP(N)>160T01300 
1170 IFN=1 T1=2:T2=3:T3=4:B0T 
01210 
1180 IFN=2 T1=1:T2=3:T3=4:60T 
01210 
1190 IFN=3 T1=1:T2=2:T3M:60T 
01210 
1200 T1=1:T2=2:T3=3 
1210 IFIP(T1)=3 GOT01410 
1220 IFIP(T2)=3 G0T01410 
1230 IFIP(T3)=3 G0T01410 
1240 C(N)=RND(8):IFC(N)=N GOT 
01260 

1250 G0T01410 
1260 IFC(N)=4 C(N)=5 
1270 IFC(N)=1 C(N)=7 
1280 IFio=5 C(N)=3 
1290 XF(N)=RND(550)+600:XINC( 
N)=(XF(N)-250)DIV22:YINC(N)=-3 
2:«OVE250,900:GCOLO,C(N):VDU5 
230 : H0VE250 , 900: GCOLO , 7: VDU5 2 
29:X(M)=250:Y(N)=900:IP(N)=2:0 
X(N)=X(N):0Y(N)=Y(N):G0T01300 

1300 IF0Y(N)<=550 COLM 

1310 H0VEOX(N),OY(N):GC0L0,C0 
L:VDU5 228 

1320 X(N)=X(N)+XINC(N) 

1330 Y(N)=Y(N)+YINC(N) 

1340 PROCboat 

1350 S0UND1,1,-N*4B,2 

1360 MOVEX(N) ,Y (N) :GC0L0,7: VD 
U5 229 

1370 H0VEX(N),YIN):6C0L0,C(N) 
:VDU 230 

1380 OX(N)=X(N):OY(N)=Y(N) 

1390 IP(N)=IP(N)+1 

1400 IFIP(N)=22 IP(N)=1:GCQLQ 
,4:VDU8:VDU5 228:PR0Ccheck:G0T 
01410 

1410 ENDPROC 

1420 : 

1430 DEFPRQCcheck 

1440 P=(X(N)+32)DIV64 

1450 IFP=XP C0=C0+1:60T01480 

1460 IFP=XP+1 CD=C0+1:60T0148 


1470 G0TO151O 

1480 IFHAN>0 CO=CO-1:60T01510 

1490 NAN=C(N) 

1500 GOTO 1560 

1510 LI=LI+1 

1520 F0RKD=1T0100:NEXT 

1530 H0VEX(N),Y(N):GC0L0,7:VD 
U5 221:S0UND0,1, 14,10 

1540 F0RKD=1T0200:NEXT 

1550 H0VEX(N),Y(N):GC0L0,4:VD 
U 221 

1560 VDU4: C0L0UR132: C0L0UR2: P 
RINTTAB(6,3O);LI;TAB(16.3O)iC0 



1570 ENDPROC 

1580 : 

1590 DEFPRDCscore 

1600 C0L0UR7: COLOUR 132 

1610 VDU23,1,0;0;0;0; 

1620 F0RI7.=0 TO 255 STEP4 

1630 S0UNDil,-12,IZ,l 

1640 NEXT 

1650 PRINTTAB(0,30)"Y0UR SCOR 
E HAS ";C0 

1660 GCOLO, 4 

1670 F0RI=255T00STEP-4:S0UNDi 
1,-12,I,1:NEXT 

1680 FORKD=1T02000:NEXT 

1690 C0L0UR11:PRINTTAB(0,30)" 
***GAME STARTING*"" 

1700 F0RI=0T07:F0RJ=0T090STEP 
2:S0UNDill,-I,J,5:NEXT:NEXT 

1710 F0RKD=1T02000:NEXT 

1720 PRINTTAB(0,30)SPC(19) 

1730 ENDPROC 

1740 : 

1750 DEFPROCttaves 

1760 IFKC=4 WC=7:CH=4:G0T0178 


1770 IFMC=7 WC=4:CW=7 

1780 VDU4: COLOUR 132: COLOUR NC 

1790 PRINTTAB(2,28)M3fiTAB(3, 
22)H2l;TAB(14,28)N3*iTAB(5,19) 

mis 

1800 PRINTTAB(6,17)SH1*;TAB(1 
4,17)SWU 

1810 COLOURCH 

1820 PRINTTAB(16,20)«1$:TAB(2 
, 24 ) W3* ; TAB (5 , 20) H2*; TAB (17,21 
)H1$;TAB(17,24)N2$; 

1830 PRINTTAB(13,15)SHlt;TAB( 
5,18)SH1$ 

1840 ENDPROC 

1850 : 

I860 DEFPROCrun 

1870 IFMAN=0 GOTO 1930 

1880 IFXP=17 C0L0UR129: COLOUR 

«AN:S0UND1,-15,250,1:PRINTTAB 
(19,25)CHR$227:FORKD=1T0200:NE 
XT:S0UND1,-15,250,1:PRINTTAB(1 
9,25)SPC(1):60T01920 

1890 F0RI=4T00STEP-1 

1900 C0L0UR129: COLOUR HAN.-PRI 
NTTAB ( I , 25 ) CHR$227 : FORKD= 1 T075 
:NEXT:S0UND1,-15,250,1:PRINTTA 
B(I,25)SPC(1) 

1910 NEXT 

1920 HAN=0 

1930 ENDPROC 



This listing is included in 
this month's cassette 
tape offer. See order 
form on Page 47. 



, 



26 ELECTRON USER August 1984 




ftmmrm 




THE COLUMN THAT TAKES A LOOK INSIDE THE LATEST RELEASES 



Just 

when 
you 

thought 
it was 
safe . . . 



Bedbugs 

Optima Software 



TO quote from the game: 
"Just when you thought it was 
safe to go to sleep 
Bedbugs, the new game from 
Optima Software, should 
safely disrupt your calmest 
dreams. 

You begin with a bed alive 
with little nasties which are 
liable to nibble your feet at any 
time. 

However you needn't des- 
pair, because you are armed 
with, believe it or not, a jam 
sandwich which you use to 
swat the bugs. 

You also have a sponge to 
wipe up the sticky jam and a 
pair of false teeth that you can 
use to crunch the irritating 
fleas. 

As a last resort there's a 
telephone that you can use to 
ca 1 1 Doctor Soothe or 
Pestdeath. These two will help 
you, always provided that 
they're in to answer the phone. 

You choose your weapon 
from a "menu" on the left of 
the screen and chase the fleas 
across the bed. When you land 
on one you press Return and 
the little blighter is no more. 

You mustn't, however, swat 
your feet (ouch!), fall off the 
bed or get yourself stuck in the 
jam, for heavy penalties are 
given. 

The sound is reasonable, 
especially the familiar intro- 
duction tune, and the graphics 
are good although not striking. 

The keys are sensibly 
placed and easy to use. 




avoiding the possibility of 
accidentally pressing Break. 

All in all an original game 
for kiddies which will keep 
them occupied for hours. 

Bev Friend 

Simple, 

yet 

endless 



Animator 

Screenplay Software 



I AM almost at a loss for words 
to describe this superb pro- 
gram from Screenplay, 
previously available for the 



BBC and the Dragon. 

It is brilliantly simple in 
concept, yet the possibilities 
for its use are practically 
endless, being a program to 
create multicoloured sprites 
which can then be compiled 
into machine code for use in 
fast graphical action games. 

The sprites may be saved to 
tape, and a library of them may 
be built up for future use. 

The first program, Creator, 
allows the design of up to 63 
separate sprites, each with 
two associated figures formed 
by 180 degree rotation about 
a horizontal or vertical axis. 

Larger sprites may be 
defined, up to 30 pixels 
square, but in this case only 
nine may be created. 

They may have any colours, 
flashing or steady, and during 
the design stage the sprite is 
also shown life size for 
comparison. 

Drawing the sprite is sim- 
plicity itself, as indeed is each 
feature of this program. When 
the sprite has been saved to 
tape it can still be recalled and 
minor alterations made for 
smooth animation. 

The second main program. 
Compiler, allows previously 
saved sprites to be compiled 
into machine code for future 
use in either Basic or machine 
code programs. 

Editing may still be per- 



Irpirg^iTiT^iir 




formed at this stage, and the 
compiled code saved again 
onto tape. Extremely clear and 
detailed instructions on the 
subsequent CALL statements 
are given, as is an explanation 
of the built-in collision check- 
ing routine. 

In addition to these excel- 
lent programs, there are also 
two demonstrations. One is a 
game called Dambuster, with 
modest but effective graphics, 
while the other is a marvellous 
scene in a tropical aquarium 
which I found myself staring at 
for a long time. 

However I kept coming 
back again and again to the 
superb Creator program, cre- 
ating endless multicoloured 



> 



STOP THE BEASTIES! 



Centipede 

Superior Software 



ANOTHER entry into the 
insect world. A long, hungry 
caterpillar wends its way from 
the top of the screen to the 
bottom where you are located. 

Can you stop the vicious 
little beastie or will it eat you 
alive? There are six skill levels 
to keep you on your toes. 

You dodge across the 
bottom of the screen using the 
Z and X keys to control 
movement, hitting the Delete 
key to blow the centipede to 
kingdom come. 



While you're doing this you 
have to keep your eye open for 
the nasty spider that hangs 
around your end of the screen 
as he, too, will eat you if he 
can. 

Also the poor, inoffensive 
little snail which wanders 
across the screen is worth a 
shot or two for, harmless 
though it is, it's worth 1,000 
points. Collect 10,000 or 
20,000 points and you get 
extra lives. 

The sound and graphics are 
very good, the instructions 
clear and the choice of keys 
simple to use. 

It's an amusing and enter- 
taining game for those with 




ELECTRON COMPUTER 



i. 



fast fingers and a dislike of 
creepie-crawlies. Peter Gray 



August 1984 ELECTRON USER 27 



From Page 27 

sprites simply because it was 
so easy and such tremendous 
fun. 

This package is excellent 
value for money, being a very 
useful tool for the budding 
programmer. There is even a 
competition for an original 
program using sprites made 
with Animator, with a first 
prize of £200. I have the 
feeling that they will receive a 
lot of entries. Phil Tayler 

Defuse 
those 



TNT 



pear, so you can't go that way 
again. 

You can, however, slide the 
row of blocks that you are on 
left and right but you have to 
be both fast and cunning. 

If you manage to survive 
the first level you're "rewar- 
ded" with another screen 
where the countdown starts at 
40. 

Complete that and the next 
level has stamping boots that 
chase you round the grid. I 
don't understand that last part, 
but it's great fun. 

With highly impressive gra- 
phics and sound, and easy to 
use keys the game appeals to 
all ages and is great fun for all 
the family. A highly original 
and compelling game. 

Eileen Young 



Friendly warning 

become 



Electron Aid 

Dynabyte Software 



THIS super utility program 
actually contains a suite of two 
very helpful and easy-to-use 
facilities for the Electron. The 
loading program presents the 
user with the option to select 
Character or Soundlab. 

The first allows the user to 
define up to 128 different 
characters (if PAGE is reset as 
appropriate), while the second 
encourages constructive use 
of sound ENVELOPES with 
various SOUND statements. 

Neither, of course, allows 
the user to do anything that 



cannot be done anyway with 
help from the User Guide, but 
these utilities are extemely 
user-friendly. 

On selecting Character the 
user replies to various screen 
prompts in order to select 
Mode (all available), and fore- 
ground and background col- 
ours. 

Once this is settled the 
option to start from scratch, or 
whether to redefine an existing 
shape, is offered. 

One way in which this may 
be of considerable use is 



bomb s a disappointing statistic 



Danger UXB 

Program Power 



ONE of the most original 
games I've come across so far. 
Danger UXB from Program 
Power, gripped my attention 
from the start and kept firm 
hold. 

You are placed in the centre 
of a block of pathways 
consisting of blue squares, 
some of which bear a skull and 
crossbones. 

The skulls mark the position 
of lethal TNT bombs. One after 
another their timers start, 
counting down from 60 to 
when, unless you've defused 
them, they explode taking you 
with them. 

Not only that but once 
you've used one set of squares 
to reach a bomb they disap- 



"i" t k ■ * * * - ■ ■* 




Elementary Statistics 

Garland Computing 

THIS cassette of four pro- 
grams and a single page of 
documentation comes from 
Garland's educational series, 
Learning Maths. 

The package is aimed at 
children aged about 9-12 
years and is for school or home 
use on either an Electron or 
BBC Micro. 

Garland has a good repu- 
tation for educational software 
for the BBC Micro but this 
package doesn't really live up 
to expectations, failing to 
make full use of the 
computer's facilities. 

Furthermore its title is 
slightly misleading in that the 
programs are mainly con- 
cerned with data collection 
and display rather than the 
computation of statistical par- 
ameters. 

After chaining the Index 
program, which displays Gar- 
land's logo, the user is asked to 
pick one of three programs, 
Barchart, Piechart or Scatter 
by typing CHAIN "Program 
name". 

Unfortunately there is much 
room for operator error here 
and the loading sequence 
could be improved. 

Barchart allows the user to 
label, input, add to and 



LEARNING 
MATHS 




m 



6) 





ELEMENTARY 
STATISTICS 



QARLAMO EDUCATIONAL 

Electron /BBC 






compare up to 10 groups of 
data in the form of a frequency 
table or a barchart (not a 
histogram, as the document- 
ation reminds us). 

The data entry sequence 
may be upset by entry of large 
values, and is also drab as it 
doesn't utilise colour or sound. 
The barchart itself is in colour. 

Negative numbers are also 
allowed on data entry, but are 
not properly displayed on the 
barchart. 

Piechart is similar to the 
previous program and allows 
the user to enter and compare 
values for up to six groups of 
data. 

The frequency table here 
also shows the angles (in 
degrees) used in the piechart. 



Again, the actual displayed 
chart is in colour. 

In this program however, 
data cannot be altered or 
added. 

Scatter plots the values of 
two groups of related data on a 
scattergram. First the axes are 
labelled and the maximum 
limits set, then each data item 
is plotted on the graph as the 
values are entered. 

When all data has been 
entered - up to 1 00 values - 
the mean is automatically 
marked on the display. I liked 
this one with its instant 
plotting. It would be very easy 
to fiddle results and enter 
values which sat along a nice 
straight line. 

Unfortunately this program 
does not allow for the correc- 
tion or addition of data. 

Overall the programs 
provide good value for money 
as a simple teaching aid but 
would be much more valuable 
for long term use in data 
collection and display if there 
were more facilities for error 
correction, saving of data and 
printout routines. 

All the programs, however, 
are written entirely in Basic 
and can be used on either 
cassette or disc systems and 
could therefore be readily 
amended to suit individual 
users. 

Mike Mahon 



28 ELECTRON USER August 1984 



you'll 
addicted 



animation. A figure may be 
defined as one Ascii character 
and then copied to a second. 

The second can then be 
edited to allow the slight 
changes necessary for smooth 
animation. Both versions of 
the shape thus remain avail- 
able for recall. 

Single key entry is provided, 
with the number keys control- 
ling the various colours, edit- 
ing and so on. 

Key 8 will even list on 
screen the VDU23 lines, 
which can then be copied for 
future use. 

A similar approach has 
been used in Soundlab, with a 
very fun approach to that 
bewildering world of 
envelopes. 

There are preset 
ENVELOPES - up to seven can 
be programmed -and up to 15 
sound commands may also be 
accessed. 

They are easily tested, 
using single key again, or 
edited by use of the number 
keys and cursor control. 

The sound controls are 
shown on screen in the format 
& FC, A,P, D while the 
ENVELOPE is shown, 
although not those numbers 
which are merely there for the 
infamous BBC compatibility. 

Any ENVELOPE may be 
paired with any SOUND state- 
ment to gain an insight into the 
possibilities. 

In addition the whole range 
of SOUND commands can be 
played one after the other, 
which in my case always 
sounded pretty ghastly. 

Again, no more is gained 
than can be learned from the 
User Guide, but the program 
does all the work for you and 
shows you your current pieces 
on screen. 

The listings of any good 
sounds produced may be 
obtained for future use. 

I found this to be a 
fascinating program to work 
with, but I must warn you that 
it soon becomes almost as 
addictive as your favourite 

games. 

Phil Tayler 



File Handler 

Diatsoft 



THE cassette inlays from Dial- 
soft do not really attempt to 
sell the product, which is a pity 
as the cassette inside contains 
a fairly good filing system 
program. 

Many people would wish to 
keep records of the card index 
type, whether for personal use 
(addresses, recipes etc), or for 
semi-personal applications 
(club membership, software 
records). 

Your micro allows you to 
keep a file with these details, 
the data then being loaded 
into another database pro- 
gram, in this case File Handler. 

The data can be mani- 
pulated to produce lists in 
alphabetical or numerical 
order, or to search for a 
particular entry. 

The trouble with all tape- 
based database programs is 
speed - a large file takes some 
considerable time to load, 
whereas a disc system 
accesses data far more rapidly. 
Roll on disc drives for the 
Electron! 

This isn't the best program I 



Something 
missing... 




have ever seen of its type, 
although there are areas in 
which it will stand comparison 
with others. 

The speed of sorting is 
acceptable and the screen 
displays clear and legible. The 
program, however, lacks 
something in the area of 
user-friendliness, using jargon 
phrases like "file extent' 
without further explanation. 

However one quickly gets 
used to these phrases, and it is 
then relatively easy to enter 
data or interrogate the file. 



The size of record which can 
be catered for varies with the 
number of fields. For instance, 
200 records can be entered 
across four fields, while only 
80 may be input if the number 
of fields is increased to 
10. 

It is also a simple matter to 
extend a file (if there is room) 
or to alter data, although the 
new data has to be saved to 
tape once again. 

A sample file is included in 
the program, although I did not 
succeed in loading it. 

I also found myself wonder- 
ing why all serious programs 
have to be presented in black 
and white. 

The program is listable, and 
it is relatively easy to alter 
screens to allow colour coding 
of the various pages. 

Incidentally, the program is 
completely compatible with 
the BBC Micro. 

Philip Tayler 



A winner - as sure as 

eggs is eggs! 



Chuckie Egg 

A&F Software 



REMEMBER the old arcade 
game where you had the 
unnerving task of leaping over 
seemingly endless gaps in 
your path, climbing ladders 
and being chased by ghoulies, 
ghosties and beasties as you 
progressed? 

Were you addicted, as I 
was? If so, then Chuckie Egg, 
the new game from A&F 
Software, will be right up your 
street. 

You control a cute little man 
with fast moving' legs who 
starts at the bottom of the 
screen and has the task of 
collecting all the eggs. 

This has to be done before 
the nasties get out and eat all 
the corn. And be warned, if you 
bump into a nasty you're a 
gonner. 

It is also wise to keep an eye 
on the crazy duck in the cage 



at the top left. If she gets out 
you've had yourchips-withor 
without eggs. 

It's not easy, but you do 
have a stock of lives to get 
through before your little man 
is annihilated. 

Once one level is cleared of 
eggs you progress higher, 
progressively harder with lifts 
and landing stages adding to 
the action. 

You've got to be quick 
thinking and have fast reac- 
tions to collect all your eggs. 

The sound and graphics are 
excellent and the key allo- 
cation is particularly good. 
Although the program gives 
you one set of keys you can 
choose your own, a feature 
more software houses should 
follow. 

It's a great game, compel- 




ling and entertaining and 
should appeal to all ages. A 
winner. 

Trevor Roberts 



August 1984 ELECTRON USER 29 



Here's a quick and easy way to get things moving on your display screen 



SCROLLER, by ADAM 
WORTLEY, is a utility pro- 
gram that produces a 
banner display moving 
along the bottom of the 
screen. 

You simply put any 
message you want into the 
program and the Electron 
will display it. 

To change the message 
just copy line 40 and 
replace the string inside the 
inverted commas with your 
own. Keep it the same 



length as Adam's, or fill 
yours out with spaces. It's 
as easy as that. 

As you'll see, the mess- 
age scrolls from right to 
left. 

Can you make it go 

from left to right? And how 

about one that goes from 

top to bottom? Or from 

corner to corner? 

Scroller isn't just a 

useful screen utility, it's a 
challenge to your own 
programming skills. 



10 REM Side Scroller 
20 REM by Adai Wortlev 
30 REH (0 ELECTRON USER 
40 MODE 1 

:VDU 23,1 ,0;0;0;0; 

:PR0CSCR0LL(3,15,"Side« 

ays Scroller by Adai 
HortleyH',2,150 

,25) 
50 END 
60 DEF PROCSCROLLUJ 

,A$,C,P,N) 
70 LET Bf=A$+A* 
80 COLOUR C 



90 FOR H=l TO N 
100 FOR S=l TO LEN A$ 

110 LET R=RND(13)+1 

:IF R=8 

THEN GOTO 110 
120 VDU 19 t C,R,0 f 0,0 
130 FOR M TO 200-P 

(KIT 
140 PRINT TAB(W>; 

NID$(Bt,S,LEN AD 

150 NEXT S 
160 NEXT H 
170 ENDPR0C 



KAY 



COMPUTER 
PRODUCTS 



PROFESSIONAL 
PROGRAMS FOR 
THE MODEL B 
AND ELECTRON 



LOW SUMMER PRICES EACH TAPE ONLY £5.95 (Except H.O.H.) 

HOUSE OF HORRORS (B)(E) £6.95 




GHOSTS ind ZOMBIES "and 'matching wits with a MUMMY. WEREWOLF, and VAMPIRE. 5 floors full of odd CORRIDORS BROKEN FLOORBOARDS, a. 
SECRET PASSAGES await you. Superb sound effects and graphics. Can be played using either keyboard or joyst.cks. Top table. Pause opt.on. 



EARLY YEARS <B)(E) For children between 3-6 years of age. 
These two packages give an adult or older child a means to take a 
younger child through a series of simple game type tasks to 
enforce ideas. The emphasis is on learning through fun. Topics 
covered include subtraction, addition, recognition, colour, shapes, 
sizes, sounds/notes, co-ordination, distances, estimates, directions. 

EARLY YEARS 1 

A) MICKEY THE MONKEY and his apple tree make subtraction fun. 

Bl COLOUR BLOCKS bring sizes and colour into perspective. 
C) MERRY MUSIC turns the keyboard into a musical keyboard. 
Dl FUNNY FACES presents a line up. which one is the suspect? 
E| FRED THE FROG needs co-ordinated help to get across the pond. 

EARLY YEARS 2 

A) THE POND seems very active today 

Bl SPEEO is required to keep the cake on the conveyor belt. 

C) DIRECTIONS seem to be needed by everyone in Orion village. 

D) ORDER the blocks. 

E) SID THE SPIDER needs some help to get out of the maze. 



ELECTRON PROGRAM CAN BE USED WITH 
FIRST BYTE JOYSTICK INTERFACES 

Watch out for HOUSE OF HORRORS at 

local dealers. 

Dealer enquiries welcome. 

All prices are FULLY inclusive for UK orders. 
Please add £1 per tape for non-UK addresses. 

Cheques/P.O.'s should be made payable to 

KAY-ESS Computer Products. 

When ordering please state BBC or Electron. 

A vailable for: 

(E) Electron IB) BBC Model B 

FREE with all orders (Except H.O.H.) 

our 3 level version of 
NOUGHTS AND CROSSES!!! 



ALSO AVAILABLE: 

STAR HAWKS (B) <E) - DESIGN (B) (E) 

- HANGMAN (B) (E) - SPACE TRAFFIC 
CONTROLLER <B> (E) - HORSES (B) (E) 

- SPACE TANK (B) 



KAY-ESS Computer Products, 
1 1 Buttercup Close, 
Romleighs Park, 
Harold Wood, 
Essex RM3 OXF. 



30 ELECTRON USER August 1984 




IMIGEL PETERS welcomes the arrival 
of a print port for the Electron 



at last ■ 



ONE ot the niygling things 
about working for Election 
User is, that until now, 
we've had to produce our 
program listings on a - dare 
I say it - BBC Micro. This 
was because the Electron 
had no way to use a printer. 

Now, however, with the 
new Print Port from Signpoint, 
things have changed. 

The Print Port is a small, 
flat, rectangular black box 
which looks very similar to the 
Joyport reviewed in the June 
issue. 

It attaches to the expansion 
port at the back of the Electron 
and takes its power from it. 

The Port connects to the 
printer by way of some three 
and a half feet of grey ribbon 
cable. Full marks to Signpoint 
for not stinting on the cable as 
some firms do. 

The Electron operating 
system, although very similar 
to the BBC Micro's, wasn't 
designed for use with a printer. 

Because of this, special 
software has to be loaded into 
the Electron from a tape 
cassette. It is this software 
that activates the Print Port 
and allows it to use a printer. 

At first I thought that 
loading the software would be 
tedious, but I soon learnt 
differently. Ail you do is enter 
CH."" and the program loads 
itself in under half a minute. 

A *FX call then activates 
the software and the Print Port 



is ready for action. 

The software sits below 
Basic storage out of the way of 
the programs you type in. It 
stays here even if the Break 
key is pressed. 

In the rare event that one of 
the programs you run should 
try to use the same memory 
space as the Print Port 
software Signpoint give four 
versions of it. 

These are exactly the same 
program, they just sit in 
different places in the 
memory. It's very unlikely that 
all four won't work! 

Once the Print Port is set up 
it is up to you to decide how to 
use it. If you want to print out 
everything that appears on the 
screen, then you just use the 
Ctrl + B and Ctrl + C key combi 
nations familiar to users of the 
BBC Micro. 

To get a hard copy listing 
you just select the printer 
using Ctrl+B, and type LIST as 
normal. The listing will appear 
both on the screen and on the 
printer. 

Ctrl + C stops the screen 



output going to the printer. 
(It's amazing how much easier 
it is to debug a program from a 
listing rather than from the 
screen.) 

Using Print Port is easy, and 
very well explained in the three 
explanatory sheets that come 
with it However you don't 
always want everything that 
appears on screen to be 
printed out on hard copy. 

The Print Port allows the 
use of the VDU2 and VDU3 
commands to switch the 
printer on and off from inside 
programs. This allows you to 
choose what you want printed 
out from a program and when. 
Program I shows how it is 
done, with Figure I showing 
what the output is. 

Incidentally, both these 
were printed out from an 
Electron using the Print Port. 
Who needs a BBC Micro now! 

The Port works with any 
printer that conforms to the 
Centronics parallel interface 
standard such as the Epson or 
Brother printers. It also allows 
the Electron to pass control 



codes to the printer. 

These control codes are 
numbers that affect the way 
that the printer works, for 
example producing italic or 
bold type or double spacing 
the lines. 

Codes vary from printer to 
printer, and are given in the 
manuals. But beware! Not 
every printer manual is as 
clearly written as the explan- 
atory sheets that come with 
the Print Port. 

I was very impressed with 
the device. Quick and simple 
to use and well explained, it 
adds a whole new dimension 
to the Electron, giving me all 
the facilities that previously 
were only available on the 
BBC Micro. 

I can't think of a higher 
recommendation. 







Program I 
10 VDU2 

20 PRINT "This is an exaiple prograi" 
30 PRINT -using the Signpoint Electron 
40 PRINPcentronics print port" 

50 VDU3 _ 

Figure I 

This is an example proqrai 
using the Signpoint Electron 
Centronics print port 




Example of the various 
type styles available 



M is is 




THIS IS CGWENSED , 

THIS IS ITALIC 
PRINTING. 

THIS IS BOLD 
PRINTING. 

August 1984 ELECTRON USER 31 




CASTLES of Sand is an 
orginal game where you 
don't have to leave your 
home to experience the 
frustration of building a 
sandcastle only to have it 
washed away by the sea! 

The game begins with 
attractive titles displayed fol 
lowed by instructions and the 
level of play option level 3 
being the hardest. 

The screen is then drawn 
with your empty sandcastle 
red with blue crosses ■ in the 
centre. There are piles of 
yellow sand on either side 
which you must collect and 
use to fill in your sandcastle. 

When you have done this, 
suitable congratulations are 
issued and a harder beach 
displayed. 

The sand at the top of the 
screen acts as a barrier to the 
sea which is slowly advancing 
to drown you. Beware any 
gaps in this barrier fill them 
in quick or the sea will come 
rushing through. 

The sea cannot harm your 
castle or kill you by reaching 
the bottom of the screen it 
only drowns you if you are 
foolish enough to go for a 
paddle! 

Any sand touched bv the 
sea - except that in the castle 
- will slowly be eaten away so 
if you are not quick enough 
you may need extra sand from 
the barrier to complete your 
castle. 

If so. beware the hungry 
sandworm.lt will eat any sand 
you may be carrying if it 
catches you or any left in its 
path. Once lost, it cannot be 
recovered. 

At the bottom of the screen 
your SCORE (25 points for 
each block of the castle filled 
in), BONUS (slowly declining) 
and BEACH (screen you are 
currently playing) are dis- 
played. With each new BEACH 
the sea eats the sand away 
quicker and the barrier is 
smaller. 

When you are eventually 
killed, either by drowning or 
loss of bonus, a hi-score table 
is displayed. Enter your name 
then press Return. 

If you wish to save the 
names and scores for another 
day, press Ctrl Space and you 
will be given a load/save 
option. 

MARTIN HOLLIS 



i 



■* 



■ \- 







*o 



. . I ' * 



PROCiinit 

PROCinit 

PROCtitles 
PROCinstr 
PROCc 
PROCend 



PROCEDURES 

Sets up variables for beginning of 
program. 

Sets up variables for beginning of 
game. 

Displays opening titles. 
Displays instructions. 
Switches cursor off. 
Called when an error is met. 



PROCtext & PROCnum Prints BONUS, BEACH, SCORE 



(N%,X,Y) 

PROCmove 

PROCIeft/PROCright/ 

PROCup/PROCdown 

PROCdraw(D°o ,DY%) 

PROCdeadcheck 

PROCscores 

PROCsave 

PROCdig/PROCfill 

PROCrestore 



characters and numbers at bottom of 

screen. 

Tests for keys pressed and calls 

appropriate PROC. 

Call PROCdraw to move man. 

Moves man in X.Y direction. 

Checks to see if you are dead. 

Displays hi-score table. 

Gives option to save hi-score table. 

To dig or drop sand. 

Restores all necessary values when 

castle filled in. 



P°o (19,26) 
W% (19) 
H%(10),H$(10) 



DIMs 

Stores what is at that position on screen. 
Remembers Y coordinates of nth wave. 
Remembers hi-score and hi-score names. 



A"o,B l \,,C"o,l\] 

CR% 

H% 

S% 

WP% 

X%,Y% 

BONUS% 

DEAD% 

FAST% 

LEVEL% 

LOOP°o 

SAND"o 

WX%WY% 



NUMERIC VARIABLES 

%,Z% General loop counters. 

True if you are carrying sand. 

Level of difficulty. 

Score. 

Wave now being moved. 

Coordinates of man. 

Amount of time left. 

True if you are dead. 

True if game in fast mode. 

Which beach is being played. 

General loop counter. 

How many blocks to fill in on sandcastle. 

Coordinates of worm. 



These have general uses. 



STRING VARIABLES 

A$,B$,F$,G$, 

L$,I\I$,S$,T$ 

LE$,RI$,UP$,DO$ Left, right, up. down. (You may change the 

initial values of these which are set at lines 

410 440.) 

TT$ The keys which the computer checks while 

game is in progress (except Space and 
Shift which are controlled by INKEY (-n)). 

W$ Sandworm. 



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Castles of Sand listing 



ICREH * CASTLES OF SAND * 
20REH * BY MARTIN HOLMS 

:0REH * IC! ELECTRON USER 

4C4WERROR KOGEi: PROCc: PRO 
Cer.d 

5G*0PTi,l 
WftOPTZ.l 
70*0PT3,6 
30KQ0E4 
?0PR0Cc 

1007DU1?,! ,4,0,0,0 
110VDU23,224, 1,1,129,195,2 

CC ICC f?f fcft 

::0FR0Ctitles 

170M0DE6 

MOPROCc 

150PR0Cinstr 

160REST0RE1460 

170BWELQPE1, 8,0. 0,0,16, 11 
,50.3,-4,0,0,126,40 

:eOVDU23,225,56,120.240,24 
0,192,0,0,0 



190VDU23,226,4,6,15,31,15, 
7,2,0 

:OOVDU23,227,0,0,0,16,48,2 
45,124,60 

210VDU23, 228,0,112,112, 32, 
243,32,90,136 

220VDU23, 229, 0,1 12,114, 37, 
255,39,32,136 

Z30VDU23 , 230 . , 24 . 36 , 36 , 36 
.36,24,0 

240'.'DU23,231,0,16,48,16,16 
,16,56.0 

250VDU23,232,0,60,4,4,60,3 

n 60 

2c 0VDU23 . 233 , , 60 , 4 , 23 , 4 , 4 

,60,0 

270VDU23,234,0,36,36,60,4, 
4.4,0 

280VDU23,235,0,60,32,60,4, 

4,60,0 

290VEU23,236,0,60,32,60,36 
.36,60,0 

Turn to Page 53 



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ft 



Make light wcrk cf listings 

To save your fingers most of the listings in Electron User have 
been put on tape. Eight are now available — for the February, 
March, April, May, June, July and August issues, plus a bumper 
tape of all the programs from the introductory issues. 

On the A u g ust tape: 

SANDCASTLE The Electron seaside outing. KNOCKOUT Bouncing balls batter brick 
walls. PARACHUTE Keep the skydivers dry. LETTERS Large letters for your screen. 
SUPER-SPELL Test your spelling. ON YOUR BIKE Pedal power comes to your 
Electron. SCROLLER Sliced strings slide sideways. 
FAST ELLIPSE Speedy graphics. NOTEBOOK Lines and patterns explained. 

On the July ta pe: 

GOLF A day on the links with your Electron. SOLITAIRE The classic solo logic game. 
TALL LETTERS Large characters made simple. BANK ACCOUNT Keep track of your 
money. CHARTIST 3D graphs. FORMULAE Areas, volumes and angles. NOTEBOOK 
Time table. 

On the June ta pe: 

MONEY MAZE Avoid the ghosts to get the cash. CODE BREAKER A mastermind is 
needed to crack the code. ALIEN See little green men - the Electron way! SETUP 
Colour commands without tears. CRYSTALS Beautiful graphics. LASER SHOOT OUT 
An intergalactic shooting gallery. SMILER Have a nice day! 

On the Ma ytape: 

RALLY DRIVER High speed car control. SPACE PODS More aliens to annihilate. 
CODER Secret messages made simple. FRUIT MACHINE Spin the wheels to win. 
CHASER Avoid your opponent to survive. TIC-TAC-TOE Electron noughts and crosses. 
ELECTRON DRAUGHTSMAN Create and save Electron masterpieces. SHEEP A 
program for insomniacs. MATHS HIKE Mental arithmetic. MESSAGE VDU commands 
in action. 

On the April ta pe: 

SPACEHIKE A hopping arcade classic. FRIEZE Electron wallpaper. PELICAN Cross 
roads safely. CHESSTIMER Clock your moves. ASTEROID Space is a minefield. 
LIMERICK Automatic rhymes. ROMAN Numbers in the ancient way. BUNNYBLITZ 
The Easter program. DOGDUCK The classic logic game. 



X 1 



A 



On the March tape: 

CHICKEN Let dangerous drivers test your nerve. COFFEE 

A tantalising word game from Down Under. PARKY'S PERIL Parky's lost in an invisible 
maze. REACTION TIMER How fast are you ? BRAINTEASER A puzzling program. 
COUNTER Mental arithmetic can be fun! PAPER, SCISSORS, STONE Out-guess your 
Electron. CHARACTER GENERATOR Create shapes with this utility. FUNNY 
POLYGONS Fast graphics going round in circles. 

On the Februar y tape: 

NUMBER BALANCE Test your powers of mental arithmetic. CALCULATOR Make your 
Electron a calculator. DOILIES Multi-coloured patterns galore. TOWERS OF HANOI 
The age old puzzle. LUNAR LANDER Test your skill as an astronaut. POSITRON 
INVADERS A version of the old arcade favourite. MOON RESCUE Avoid the asteroids 
and save the spacemen. 

On the introductor y tape: 

ANAGRAM Sort out the jumbled letters. DOODLE Multicoloured graphics. EUROMAP 
Test your geography. KALEIDOSCOPE Electron graphics run riot. CAPITALS New upper 
case letters. ROCKET, WHEEL, CANDLE Three fireworks programs. BOMBER Drop 
the bombs before you crash. DUCK Simple animation. METEORS Collisions in space. 
COMBINATIONS Crack the code. BUZZ WORD GENERATOR Let the Electron help 
you impress. 



HOW TO ORDER 



Please send me the following Electron User cassette tapes 

Fourteen programs from the August issue £ 

Ten programs from the July issue £ 

Ten programs from the June issue £ 

Twelve programs from the May issue £ 

Eleven programs from the April issue £ 

Twelve programs from the March issue £ 

Nine programs from the February issue £ 

26 programs from the introductory issues £ . 

I enclose the sum of £ « 



Name POST TO: Tape Offer, 

Address Electron User, Europa House, 

68 Chester Road, Hazel Grove, 
Stockport SK7 5NY. 



<1** 

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34 ELECTRON USER August 1984 



PEDAL power comes to 
the Electron with DAVID 
McLAC HAN's clever and 
amusing graphics pro- 
gram. On Your Bike. 

It is a well structured, 
easy-to-follow program 
that's an excellent exam- 
ple of Electron anima- 
tion. 



k4 



h n rt *♦ 4* l* » ns 

g.,|, p - , fr.a,.g..a.fr . fi"tt 

g , , a„g, , 3. . g. .g i . g . . n„g , ,g ,g, g. . Q . ■§■ i 








s § g s H §4#| HHHHHI itffl ^ g i j g HI 5 5 1 tt gfttj 




VARIABLES 

Se s vertical J* 
House horizontal J* 

House vertical axis. 

Leg positions. 

Screen count. 

Old position of bike. 

Old position of 'eg_ 



U% 

X% 

Y% 

AA% 

BB% 

XX% 

aa% 

OLDX% 
OLDXX% 



10 REH QN YOUR BIKE 

20 REH By David HcLachlan 

30 REH (c) Electron User 

40 HODE 2 

50 PROCCHftRACTERS 

60 PR0CINIT 

70 PR0CSCREEN1 

iPROCHALL 

iPROCLAMPPOST 
80 REH m HA IN LOOP 

*** 

90 REPEAT 

100 6CQL 0,3 

110 QQX=B8X+1 

120 IF Q8X=2 

THEN XX=1200 

jPROCSCREENI 

: PRQCHALL 

:PR0CLAHPP0ST 

: PR0CTRUCK 



130 IF QQX=3 
THEN XX=1200 
iPROCHALL 
: PR0CTRUCK 
:PRQCSCREEN1 
iPROCFENCE 
iPRQCCOH 
:PR0CLAHPP0ST 

140 IF QQX=4 
THEN PRQCC0H 
iPROCSCREENl 
iPROCFENCE 
: PROCHOUSE 
:GC0L 0,3 
iPROCLAHPPOST 

150 IF QQX=5 
THEN BM2M 
: PR0CFENCE 
iPROCSCREENl 
iPROCHALL 




230 PnoCIIMIT 
820 PROCSCREEN1 
1410 PROCCOW 
1540 PROCWALL 
970 PROCTRUCK 
1190 PROCFEIMCE 
1280 PROCHOUSE 
910 PROCLAMPPOST 
660 PROCMOVEBIKE 



PROCEDURES 



Sets up all variables. 
Draws the road. 
Draws the cow. 
Draws the wall. 
Draws the truck. 
Draws the fence. 
Draws the house. 
Draws the lamp posts. 
Moves the bike. 



iPROCLAHPPOST 
: PROCTRUCK 
iPROCCOH 
: PROCHOUSE 

160 IF 8QX=6 

THEN SOTO 60 

170 XX=ll00 

180 REPEAT 

190 PROCMOVEBIKE 

200 UNTIL H<=100 

210 UNTIL FALSE 

220 REH "SETUP VARIABLES 

IH1 

230 DEF PROCINIT 

240 CLS 

250 ENVELOPE l, 1,-2,-2 

,0,9,9,0,126,0,0,-126 

,126,126 

260 XXZ-233 

: Q0X=0 



:XM100 
:YX=440 
270 0LDXX=XX 
:0LDYX=YX 
280 OLDXXX=XXX 
290 VDU 5 
BC0L 3,7 
HOVE XX, YX 
VDU 225,8,8,10,226 
, XXX, 227 

300 VDU 5 
310 ENDPROC 

320 REH **** CALL CHARACTER 
S **»t 

330 DEF PROCCHARACTERS 
340 VDU 23,225,7,11,7 



This listing is included in 
this month's cassette 
tape offer. See order 
form on Page 47. 



August 1984 ELECTRON USER 35 



On your Bike listing 



From Page 35 


,201,74,8B,8,8,24 


*#i* 


,540,780,660,840 






610 REN "♦* WALL **** 


970 DEF PROCTRUCK 


1350 DATA 660,680,540,610 


,1,7,235,147,255 


620 VDU 23,248,255,8,8 


980 GCOL 0,6 


,540,780,540,610,380 


:REH "HEAD** 


,8,255,64,64,64 


990 IF QQX=3 


,620 


350 VDU 23,226,25,102 


630 VDU 23,249,0,247,247 


THEN 6C0L 0,0 


1360 NEXT 


,70,137,153,66,102 


,247,0,191,191,191 


1000 HOVE 400,550 


1370 RESTORE 


,24 


640 ENDPROC 


1010 VDU 238,8,10,239 


1380 HOVE 640,700 


:REH "FRONT WHEEL" 


650 REN **** NOVENENT 


1020 6C0L 0,4 


:DRAH 700,700 


360 VDU 23,227,152,102 


OF BIKE MM 


1030 IF QQ%=3 


:DRAW 700,640 


,98,145,249,66,102 


660 DEF PROCNOVEBIKE 


THEN BCOL 0,0 


.-DRAW 640,640 


,24 


670 IF INKEY (-1) 


1040 HOVE 250,500 


:DRAW 640,700 


:REH "BACK WHEEL** 


THEN XX=XZ-32 


:H0VE 250,600 


1390 ENDPROC 


370 VDU 23,228,141,77 


S60TD 690 


:PL0T 85,390,600 


1400 REH HH DRAW COM 


,77,37,37,31,4,12 


680 XMM6 


1050 HOVE 250,500 


HH 


380 VDU 23,229,141,93 


690 UMIH 


:H0VE 390,600 


1410 DEF PROCCOH 


,89,49,33,63,96,0 


700 IF m=228 


:PL0T 85,390,500 


1420 6C0L 0,7 


390 VDU 23,230,141,89 


THEN BHMS3 


1060 GCOL 0,6 


1430 IF QQZ=4 


,113,33,97,223,0,0 


sSOUND 1,1,0,8 


1070 IF QQZ=3 


THEN GCOL 0,0 


400 VDU 23,231,177,113 


710 IF <XX=OLDXX)ENDPROC 


THEN GCOL 0,0 


1440 HOVE 500,700 


,65,225,33,31,0,0 


720 VDU 5 


1080 HOVE 260,498 


1450 IF QQX=5 


410 VDU 23,232,177,81 


:6C0L 3,7 


1090 DRAM 260,494 


THEN HOVE 100,730 


,113,33,33,31,0,0 


730 HOVE OLDH.OLDYZ 


1100 DRAM 264,490 


1460 VDU 240,241,8,8,10 


420 VDU 23,233,153,77 


:VDU 225,8,8,10,226 


1110 DRAM 278,494 


- ,242,243,244,8,8,8 


,69,45,33,31,0,0 


,0LDm,227 


1120 DRAW 278,498 


,10,245,246,247 


430 REN ***» LAHP_P0ST 


740 HOVE XX, n 


1130 IF SOZ-3 


1470 HOVE 300,700 


m* 


750 *FX19 


THEN GCOL 0,0 


1480 IF QQX=5 


440 VDU 23,234,24,56,40 


760 VDU 225,8,8,10,226 


1140 VDU 5 


THEN HOVE 100,770 


i b , 8 ^ 8 j 6*: 1 5 


, XXX, 227 


1150 HOVE 260,560 


1490 VDU 5 


450 VDU 23,235,8,8,8,8 


770 VDU 8,8,9 


1160 PRINT "EU" 


1500 IF 0QX=4 


,8,8,8,8 


780 OLDXMX 


1170 ENDPROC 


THEN GCOL 0,0 


460 VDU 23,236,28,28,28 


790 OLDXXX=XXX 


• 1180 REH ***♦ DRAW FENCE 


1510 PRINT "moo" 


,28,28,28,28,28 


800 ENDPROC 


t**» 


1520 ENDPROC 


470 REN *m FENCE #*** 


810 REN »*** DRAW ROAD 


1190 DEF PROCFENCE 


1530 REH **** DRAW WALL 


480 VDU 23,237,170,170 


mt 


1200 GCOL 0,2 


»m 


,255,170,170,170,255 


820 DEF PR0CSCREEN1 


1210 IF QQ%=S 


1540 DEF PROCMALL 


,170 


830 BCOL 0,3 


THEN GCOL 0,0 


1550 GCOL 0,7 


490 REN HH TRUCK H*J 


B40 HOVE 0,534 


1220 HOVE 0,600 


1560 IF QQ7.=3 


500 VDU 23,238,0,120,68 


: DRAW 1280,534 


1230 FOR FENCEM TO 20 


THEN GCOL 0,0 


,68,68,68,124,254 


850 HOVE 0,370 


1240 VDU 237 


1570 HOVE 0,600 


510 VDU 23,239,254,255 


SDRAM 1280,370 


1250 NEXT 


1580 FOR WALLM TO 20 


,255,255,245,247,20 


860 FOR LM TO 1280 


1260 ENDPROC 


1590 VDU 248 


,8 


STEP 100 




1600 NEXT 


520 REN **** COM ♦*»* 




1270 REN **** DRAW HOUSE 


1610 VDU 11 


530 VDU 23,240,0,0,0,4 


870 HOVE LX.450 


»»** 


1620 GCOL 0,1 


,4,4,2,1 


:DRAM LX+30,450 


1280 DEF PROCHOUSE 


1630 IF BQX=3 


540 VDU 23,241,0,0,0,0 


880 NEXT 


1290 6C0L 0,1 


THEN GCOL 0,0 


,0,8,8,200 


890 ENDPROC 


1300 HOVE 500,610 


1640 FOR WALL^l TO 20 


550 VDU 23,242,2,2,7,31 


900 REH *♦*# DRAM LAHPPOSTS 


1310 FOR HOX=OTO 28 


1650 VDU 249 


,63,47,22,12 


mt 


1320 READ AAX.BBX 


1660 NEXT 


560 VDU 23,243,240,160 


910 DEF PROCLAHPPOST 


1330 DRAW AAX+200.BBM0 


1670 GCOL 0,7 


,160,224,248,126,255 


920 8C0L 0,7 


1340 DATA 340,600,380,620 


1680 IF DQZ=3 


,191 


930 HOVE 304,570 


,380,680,360,700,320 


THEN GCOL 0,0 


570 VDU 23,244,0,0,0,0 


:VDU 236,8,11,235 


,680,340,660,300,660 


1690 HOVE 0,570 


,0,56,254,253 


,8,11,235,8,11,234 


,300,600,340,600,340 


:DRAW 1300,570 


580 VDU 23,245,9,6,0,0 
,0,0,0,0 


940 HOVE 900,570 

:VDU 236,8,11,235 


,660,380,680,340,660 
,320,680,300,660,300 


1700 ENDPRDC 




This listing is included in 




590 VDU 23,246,63,63,35 


,8,11,235,8,11,234 


,780,400,880,600,880 


this month's cassette 




,33,97,32,32,96 


950 ENDPROC 


,540,780,300,780,540 


tape offer. See order 




600 VDU 23,247,253,253 


960 REH *«** DRAM TRUCK 


,780,600,880,660,840 


form on Page 47. 




* m 





36 ELECTRON USER August 1984 




mom 




$wm 



t 



Friendly 
book 
that's 
just that 



The Friendly Computer 
Book, Jonathan Inglis, BBC 
Publications. 



IT MAY seem strange, but 
the book I'm about to 
review isn't about the Elec- 
tron at all. It's written for 
three other micros. 

However, when I tell you 
that one of these is the BBC 
Micro then you might see why 
we're reviewing it in Electron 
User. 

Most of what it says about 
the BBC Micro applies equally 
well to the Electron so it would 
be a pity not to mention it. 
After all, why should BBC 
Micro users have all the best 
books? 

When I first saw The 
Friendly Computer Book and 
read the blurb on the back, I 
was against it straight away. 



I was convinced it would be 
one of those computer books 
which confuses being simple 
with being simplistic, and 
explaining in easily understood 
terms with talking down to 
people. 

The fact that it had cartoons 
in it didn't help my prejudices, 
either. 

Happily, though, when I 
actually got down to reading 
the book as opposed to 
reacting to it I got a very 
pleasant surprise. 

I found that it really was the 
friendly and simple introduc- 
tion to Basic programming 
that the blurb claimed it to be. 

The book starts with a 
general introduction to the 
world of computing and 
explains some of the jargon 
used. Nowhere does it go into 
things too deeply, but what it 
has to say is thorough and 
makes sense. 

It gives the answers to the 
sort of questions beginners 
have but feel too daft to ask. 

It then goes on to cover 
keyboard skills and in the third 
chapter starts on program- 
ming proper. 

The remaining ten chapters 
deal with Basic programming 
in simple, clear terms. New 
concepts are introduced grad- 
ually and logically and 
thoroughly explored in some 
delightful little programs. 

The novice is painlessly 
lead through the early key- 
words (LIST, RUN and so on), 
loops, decision making, arrays 
and simple data handling onto 
simple sound, graphics and 
animation. 

The presentation of the 
book is excellent. The listings 
are clear, the cartoons amus- 




ing and helpful, and "Chip's 
Workshop" at the end of each 
chapter adds a nice, friendly 
and educational touch to the 
main text. 

Each chapter also carries a 
summary of what it contains. 

The only reservation I have 
is that as it's written to cover 
three micros (the BBC, 
RML380Z and the Spectrum) 
the programs don't make all 
that much use of the more 
advanced structures of BBC 
Basic. 

Still, in what is meant to be 
a very elementary beginner's 
book, I can't see that's any real 
fault. 

In fact considering it covers 
three micros, each with dif- 
ferent commands, the book is 



Quantity 
-and 
quality 
too! 



40 Educational Games for 
the Electron, Vince Apps, 
Granada Publishing. 



Mr Chip from The Friendly Computer Book 



FORTY programs for less 
than £6 has got to be good 
value by any standards, but 
the real value of this book 
depends largely on the 
quality of those games. 

Here Vince Apps has writ- 
ten 40 assorted, simple pro- 
grams, some of which could 
stand on their own. 

The real purpose, I am sure, 
is to encourage young users to 
experiment with these basic 
modules, and so make them 
more suitable for their own 
particular needs. 

In this respect [he book is a 
winner as a few hints are given 
to develop each program, but 
not enough to overwhelm the 
inexperienced. 

The book's range is wide, 
from geography to anagrams, 
from Morse code to chemical 
elements. There are several 
'classic' games such as Simon 
and Mastermind, and a few 
novel ideas as well. 

I would have liked to see a 
little more explanation of some 



amazingly easy to follow, a 
tribute to whoever designed it. 

So, all in all, an excellent 
little book that I would 
unhesitatingly recommend to 
those who find the more 
traditional type of textbook too 
daunting. 

It may be a little too simple 
for some tastes but it's 
certainly one to bear in mind 
when buying a beginner's 
book for the young (and the 
not so young). 

It is a very friendly guide to 
the basics of Basic and a 
gentle introduction to micros 
for newcomers, even if they 
have an Electron and the book 
was written for a different 
machine. 

Peter Green 




of the more unusual features 
(*FX calls for example), per- 
haps through greater use of 
REM statements. 

The more experienced pro- 
grammer can always leave 
them out, while the less 
experienced would not need to 
be constantly referring back to 
the manual. 

I also found some of the 
screen illustrations rather mis- 
leading - the program itself 
turning out to be rather 
different - although most were 
fair likenesses. 

To end on a more positive 
note, the programs are excel- 
lent examples for any aspiring 
beginner, being well struc- 
tured and often modular in 
construction. 

Many children will have 
great fun using them, and will 
be learning almost by accident 
while they do! 

Phil Tayler 



August 1984 ELECTRON USER 37 



ARE there times when no 
one pays any attention to 
you and you feel like you 
are talking to a brick wall? 

Well, cheer up, ROLAND 
WADDILOVE's program 
Knockout gives you the 
chance to get your own 
back! 

Row after relentless row 
of brick walls creep up the 
screen. Your job is to stop 
any of them reaching the 
top. 

You do this by sending a 
ball - which is merrily 
bouncing across the top of 
the screen - crashing into 
the marauding masonry. 

It's easy to play as the 
space bar is the only control 
used throughout. 

It's also great fun — a 
simple but thoroughly 
enjoyable game that will 
keep you at the keyboard 
for hours. 




10REH KNOCKOUT 

20REM By R.A.Haddilove 

30 

40H0DE 1 

50PR0Cinitialise 

60PR0Cinstructions 

70H0DE 2 
80REPEAT 
90PR0Cdifficultv 

lOOPRQCset .variables 

1I0REPEAT " 

120PR0Caove.ball 

130PR0Cdrop_ball 

MOPROCknockout.bricks 

150PR0Ccheck_top_line 

160PR0Caove_iiall 

170UNTIL qaae.over 

190PR0Clost 

190PR0Cartother _gaae 
' 200UNTIL INSTRPNn'.keyf) 

210PR0Cend 

220N0DE 6 

230END 

240 

250DEF PROCinitialise 

260VDU 23,224,127,127,127,12 
7,127,127,127,0 

270VDU 23,225, 16, 32,64, 255, 6 
4,32,16,0 

280VDU 23,226,8,4,2,255,2,4, 
8,0 . 



1 




D j 1 


* 




290VDU 23,227,24,126,255,255 
,255,255,126,24 

300ENVEL0PE 1,2,4,-4,0,1,1,0 
,126,0,0,-126,126,126 

310ENVEL0PE 2,129,-1,0,0,100 
,0,0,126,0,0,-126,126,126 

320*keyio, , old:mrun:h" 

330*FX4,1 

340»Fni,0 

350*FX?29,1 

360brick$=STRIN6*(20,CHR*224) 

370best%=0 

380ENDPR0C 

390 

400DEF PROCset .variables 

410VDU 19,8,14;0;19,14,8;0; 

420VDU 23,1,0;0;0;0| 
430scoreZ=0 : levelX=3 
440rcwsZ=0 : typeZ=l 
450gaae_over»FALSE 
460F0R iX=l TO 3 
470PR0Caove_«all 
480NEXT 
490ENDPR0C 
500 

510DEF PROCaovejull 
520IF typeX=l THEN PROCbrick 
s ELSE PROCspaces 
530PRINT TAB(0,31>;next»; 
54OC0LOUR 7 
550PRINT TAB(5,0)j'SC0RE=";s 



coreX'SPC(20)j 

560IF gaae.over ENDPROC 

570PRINT CHR$226iTAB(19,2);C 
HRt225 

580ENDPR0C 

590 

600DEF PROCbricks 

610C0L0UR levelI-2 

620IF ro«Z=levelZ THEN rows 
1*0 : leven=levelX+l :" typeX= 
-typeX ELSE rowI=rot«I+l 

630nextt=brickJ 

640ENDPR0C 

650 

660DEF PROCspaces 

670IF roNsX=10 THEN ro«sX=0 
: typeX=-typeX ELSE rons2=rows 

in 

680next$=STRIN6$(20," ") 

690ENDPR0C 

700 

710DEF PROCaove ball 

720xX=l : yX=l : directionX=l 

730*FX15,1 

740S0UND 1,-15,100,1 

750REPEAT 

760IF xX=0 OR xX=19 THEN dir 
ectionX=-directionX : SOUND 1, 
-15,100,1 

770npnxX=xX+directionX 

780VDU 31,xZ,yZ,32,31,neHxZ, 



yZ,227 

790xZ=nenxZ 

800PR0Cpause(8) 

810UNTIL INKEY0=32 

820ENDPR0C 

830 

840DEF PROCdrop.ball 

850REPEAT 

860VDU 31,xZ,yZ,32,31,xZ,yZ+ 
1,227 

870S0UND Ml,-10,140-yZ*4,5 

880yX=yX+l : PR0Cpause(8) 

890pointZ=P0INT(xZ»64+32,976 
-32*yZ) 

900UNTIL yZ=31 OR pointZ 

910ENDPR0C 

920 

930DEF PROCknockout .bricks 

940IF yZ=31 ENDPROC 

950S0UND 0,-15,4,1 

960PRINT TAB(xZ,yZ);' "s 

970yZ=yZ+l 

980F0R jZ=l TO RND(levelZ)+l 

990F0R iZ=xZ-jZ TO xZ+jZ 
1000IF P0INT(iZ*64+32,1012-yZ 

*32)>0 AND yZ>0 THEN scoreZ=sc 
oreZ+9+speedZ : PRINT TAB(11,0 
>;scoreX;TAB(iX,yX>;" '; : SOU 
ND 0,-15,4,2 

1010NEXT 

1020yZ=yZ-l 



38 ELECTRON USER August 1984 



a 












■■■■1 


■HH 




■■■■■I 


PROCEDURES 


510 




250 




PROCmove. 


.wall Prints either bricks or spaces 


PROCinitialise 


Defines characters, envelope and 




along the bottom of the screen. 




switches off cursor and repeat. 


1250 




1720 




PROCIost 


Makes appropriate sound, shows 


PROCinstructions 


Prints instructions. 




bricks at top. 


1060 




1420 




PROCdifficulty 


Inputs speed of game. 


PROCanother_game Shows high score, asks whether 


400 






you want to play again. 


PROCset_variables 


Turns cursor off, sets level/score/ 
rows/type. 






710 








PROCmove_ball 


Moves ball back and forth along 








the top until the space bar is 




VARIABLES 




pressed. 


x%,y% 


Ball coordinates. 


840 




score% 


Score. 


PROCdrop_ball 


Moves ball down the screen until 


level% 


Maximum number of rows of bricks. 




brick hit or at bottom. 


rows% 


How many rows printed at bottom. 


930 




type% 


Row of spaces or bricks. 


PROCknockout_bricks 


Rubs out bricks hit, increments 


bricks$ 


Row of bricks. 




score. 


best% 


High score. 


1180 




direction% 


1 or — 1 , right or left. 


PROCcheck_top. .line 


Checks to see whether wall has 


speed% 


Speed of game. 




reached the top. 


next$ 


Next row to be printed, either bricks or spaces. 



1030NEXT 


1300IF PQINT(xZ*64+32, 1012-64 


1040ENDPROC 


) THEN PRINT TAB(xZ,2);CHR$224 


1050 


: SOUND 1,-15,RNDI100),10 


1060DEF PROCdifficulty 


1310NEXT 


1070CLS : COLOUR 3 


1320M0VE 0,948 : PLOT 21,1279 


1080PRINT — TAB(4>; "What spe 


,948 


ed ?* 


1330PR0Cpause(500) 


1090C0L0UR 1 


1340ENDPR0C 


1100PRINT'TAB(4); , (1,2 or 3) 


1350 


"■ 


1360DEF PROCpause(delayZ) 


1U0S0UND 1,-10,50,10 


1370TI«E=0 : delayZ=delayZ DI 


1120REPEAT 


V speed* 


1130speedZ=6ET-48 


1380REPEAT 


1140UNTIL speedZ<4 AND speed! 


1390UNTIL TIHE>delayZ 


>0 


1400ENDPR0C 


1150S0UND 1,-10,50,5 : CLS 


1410 


U60ENDPR0C 


1420DEF PROCanother.gaae 


1170 


1430CLS : COLOUR 3 


1180DEF PROCcheck.topJine 


1440IF bestZ<scoreZ PROChi.sc 


1190y%=1012-3*32 


ore 


1200F0R xZ=32 TO 1248 STEP 64 


1450CLS : COLOUR 6 


1210IF PQINTfxX.yZ) ga«e_over 


1460PRINT Best score: ";be 


=TRUE 


stZ 


1220NEXT 


1470PRINT""By...";naaet; 


1230ENDPR0C 


1480S0UND 1,-10,50,10 


1 1240 


1490PR0Cpause(300) 


1250DEF PROCIost 


1500C0L0UR 1 


1260speedX=l : COLOUR 8 


1510PRINT Do you want to 


1270S0UND 1,1,50,40 


play again (Y or N) ?*; 


1280S0UND 1,2,100,40 


1520S0UND 1,-10,50,10 


1290F0R xZ=0 TO 1? 


1530REPEAT 



1540key$=6ET$ 

1550UNTIL INSTRCYyNn\key*) 

1560VDU 7 : CLS 

1570ENDPR0C 

1580 

1590DEF PROChi .score 

1600bestZ=scoreZ 

1610PRINT This is the bes 

f ""score so far !" 

1620C0L0UR 5 

1630PRINT What is your na 

ae ?" 

1640C0L0UR 1 

1650PRINT'"<up to 10 letters) 

• 

1660C0L0UR 3 : VOU 23,1,1;0;0 

;0; 

1670REPEAT 

1680INPUT TABIC, 20);SPC(40);T 
AB(0,20)snaee* 

1690UNTIL LEN nanftll AND LE 
N naseJ 

1700ENDPR0C 

1710 

1720DEF PROCinstructions 

1730PRINT'TABU4) ; "KNOCKOUT" ' 
TABI13);" " 

1740C0L0UR 2 

1750PRINT'"Try to stop the Ha 
11 advancing up the" '"screen 
by knocking the bricks out Hit 



h"""a canonball." 

1760PRINT""The canonball aov 
es back and forth along" '"the 
top of the screen until the sp 
ace" ""bar is pressed. It then 

drops donn and" ""crashes int 
o the Hall." 

1770PRINT" "There are three s 
peeds, 1 is the slowest' ' "and 
each brick is worth 10 points. 

One" ""bonus point is given o 
n level 2, and two" "bonus poi 
nts are given on level 3." 

1780C0L0UR 1 

1790 PRINT'"" Press the sp 
ace bar to start..."; 

1800S0UND 1,-10,50,10 

1B10REPEAT 

1820UNTIL SET=32 

1830CLS 

1840ENDPR0C 

1850 

1860DEF PROCend 

1B70*FX4,0 

18B0»FX12,0 

1890»FX229,0 
1900ENDPR0C 



This listing is included in 
this month's cassette 
tape offer. See order 
form on Page 47. 



August 1984 ELECTRON USER 39 




The games that 
set the standard 



SEA WOLF 

So far all has gone well. You have 
successfully guided your submarine safely 
through enemy controlled waters and you are 
beginning to relax. 

Suddenly alarm bells scream in your ears 
- you are under attack! 

Desperately you scan the radar screen. 
Should you try to get him within range of 
your torpedoes, or attempt evasive tactics? 
Can you lead your crew to safety? 

BED BUGS 

The pests are after your feet and you'll have 
to move fast to stop them. Swot them with a 
jam sandwich or crunch them with your false 
teeth. 

If you're desperate you can always phone 
for help. But whatever you do, do it quickly. 
You need cunning tactics and nimble fingers! 

Bed Bugs guarantees hours of hilarity for 
the whole family. 

OMEGA PROBE 

Far out in the uncharted reaches of the 
universe lie the Omega zones from which no 
man has ever returned. 

To explore this hazardous region the 
Earth's scientists have created the Omega 
Probe - the ultimate spacecraft. 

As pilot of the probe, you face the 
unknown hazards of the Omega zones. Your 
mission: to survive. 

This fast and furious machine code game 
with its tremendous graphics and many 
unique features takes arcade games to new 
heights of programming excellence. 



games from your Acorn dealer or send off the coupon below to 



Sea Wolf 

D BBC 'B' cassette £6.95 

D Electron cassette £6.95 

D BBC 40 track disc £8.95 

□ BBC 80 track disc £8.95 



Name 



Bed Bugs 

D BBC 'B' cassette £6.95 

D Electron cassette £6.95 

D BBC 40 track disc £8.95 

D BBC 80 track disc £8.95 



Omega Probe 

□ BBC 'B' cassette £6.95 

□ Electron cassette £6.95 
D BBC 40 track disc £8.95 

□ BBC 80 track disc £8.95 



| | I enclose acheque payable 
to Optima Software Ltd. 

|~~1 I wish to pay by *Access/Visa 
— (*delete as appropriate). 



Address 



Card No.. 
Expiry date 



Signed 




this SignP°' ,nt 



Centronics 
print Port 1 - 

. trotted 1 



O 




have vo U ^ asris 

faCt *" Tte ' Have you 
use 3 f 12 teeth with rage 

surfers 

processors? _ there 

Well gnash n0 ™° ronic s 
a^ two Signpost Ceo k ^ 

Prin \ h P r re competition, 
month s tree t0 

And it oDoWntJJ do ^ 
enter. AH vo^ve . crQ 

dra w it. '^Vach of the three 
haPPen ' n . 9 nd even if you re not 
frames. And ev yQU 

,uckY ff£ your idea in 
might still see y 

prU ?' , ..<* the contest entry 
by August 3 i . , ina |. 

Ports. 



WE HAVE A WINNER 



REMEMBER the May com- 
petition where we asked 
you to think up the links 
between that month's 
Casting Agency charac- 
ters? The prize was a 
Signpoint Joyport joystick 
interface. 



We had lots of very 
clever entries, and picking 
the winner wasn't easy. 
Finally we settled on this 
poem from Paula Hatcher 
of Bognor Regis. 

The Joyport is on its 
way to her. 



Fred the Dragon's happy watching his TV, 

But the Devil's playing tricks as he's feeling crotchety. 

The TV set goes wrong and Fred's voice begins to 

quaver. 
So you'd better fetch a brolly (and maybe a lifesaverj. 

Because if Fred should start to cry. 
You've no hope of staying dry! 




LECTROIM USER contest entry form 



Fill in each frame below (in words or pictures) with your idea 
for the Micro Kid cartoon strip. Then send your entry to: 



Name 




August 1984 ELECTRON USER 41 



NIGEL PETE RS scrutinises VDU23 statements 





THE idea for Character Shaper 
came when I was helping the 
Editor sort out some of the 
Casting Agency characters 
sent in by our readers. 

Some of the diagrams 
showing how they were made 



10 REM CHARACTER SHAPER 

20 REH Nigel Peters 

30 REH (0 Electron User 

40 DIN byte$(8) 

SO PROCinput 

60 PROCprint 

70 END 

80 DEF PROCinput 

90 FOR ron-1 TO 8 
100 REPEAT 
110 INPUT "Next nuiber 

■nuiber 
120 UNTIL nuiber >«0 
AND nuiber<=255 
130 PROCbinarytroH, nuiber) 
140 NEXT roN 
150 ENDPR0C 
160 DEF PROCprint 
170 FOR ra«*l TO 8 
180 PRINT TAB(S) bytellro*) 
190 NEXT ron 
200 ENDPR0C 
210 DEF PR0Cbinary(ro« 

, nuiber) 
220 FOR loop=t TO 8 
230 IF nuiber HOD 2=0 

THEN byte$(ro«)« - '"+byt 
et(roM) 
240 IF nuiber HOD 2=1 

THEN byteflroM^'f+byt 

et(roH) 
250 nuiber«nuiber DIV 2 
260 NEXT loop 
270 ENDPR0C 



This listing is included in 
this month's cassette 
tape offer. See order 
form on Page 47. 



up were fairly small and had to 
be redrawn on a larger scale. 

This took up quite a bit of 
time - especially since the 
Editor is no artist and seems to 
hate counting. 

I decided that it would be 
far easier and more sensible if 
we got the Electron to do the 
work, so Character Shaper 
was created. 

When you come across a 
VDU23 and you want to know 
how its grid is made up, you 
just run the program. It asks 
you to enter the numbers that 
define that character and the 
grid diagram then appears on 
the screen. 

An asterisk means that that 
block is filled in, an apostrophe 
means that it's blank. 

Alternatively you could say 
that the asterisks show the 
patches of foreground colour, 
the apostrophes the back- 
ground. 

Take the case of the Devil's 
Head in the May Casting 
Agency. The VDU23 state- 
ment is: 

VDU 23,225,66,90,126, 
90,255,66,60,24 

To see how the grid is made 
up we just run the program. 






enter the last eight numbers of 
the VDU23 and Figure I 
appears on the screen. 

From this, it's easy to fill in 
the grid. Figure II shows what 
the completed grid looks like. 

So how does it work? 

If you've ever thought about 
it, you may have wondered 
how just eight numbers after a 
VDU23 manage to define a 
character of eight rows, each 
row of which has eight blocks. 

How does 255 produce a 
row of all foreground colours, 
and produce all background 
as in Figure III? 

And how does the Electron 
know that the number 3 
means that only the last two 
blocks in the row are to be 
switched on? 

The answer is that the 
Electron converts the number 
into an eight figure binary 
number. 

This isn't as mathematical 
as it might sound. The binary 
number is just the same value 
as the normal number but it's 
made up of only Os and 1s. In 
the binary system 255 rs 
11111111 while 3 is 
00000011. 

If you look back at Figure III 
you might notice that each of 



' * * 



- * - - • -* • 
'*•***** 
* ****** • 
' * • ** * * ' 
******** 
' * * ' ' * * * 
• ' **** ' * 



9 * 



* * 4 



** • • ' 



the eight blocks making up the 
row correspond to the binary 
number for that row. 

The 1 s in the binary number 
are in foreground colour, the 
Os are in background colour. 

The Electron translates the 
decimal number 3 into an 
eight figure binary number 
0000001 1 . It uses the pattern 
of that binary number to 
decide which parts of the row 
are in foreground colour. 

Figure IV shows this for the 
Devil's Head. Notice that the 
1s of the binary number 
correspond to the blocks that 
are filled in. 

Now let's have a look at 
Character Shaper which uses 
this principle to show how a 
user-defined character is 
made up. 

The first three lines are just 
the usual boring old REM 
statements telling us what the 
program is. who wrote it and 
where it comes from. You 
don't need to type them in. 

Line 40 uses a DIM state- 
ment to set up an array, byte$. 
All this does is set up nine 
string variables, byte$(0), 
byte(l), and so on to byte$(8j. 

You'll notice that the vari- 
ables that are DIMmed all 




Figure I: Foreground/ background pattern 



Figure II: Devil's Head grid 



42 ELECTRON USER August 1984 




have names that are exactly 
the same except for the 
number in the brackets, the 
subscript. This comes in useful 
when you're doing the same 
sort of thing several times over 
in a loop. 

Each of them is set to the 
null string, ", for the time 
being. The null string contains 
nothing, as you might guess 
from the fact that there is 
nothing between the inverted 
commas. 

You'll see this array of 
variables in action later in the 
program. 

Then come PROCinputand 
PROCprint and the program 
ENDs in line 70. In case you're 
wondering what all the lines 
from 80 onwards are doing, 
they're defining the 
procedures called in lines 50 
and 60. 

The parts of the program 
afterthe END can be looked on 
as appendices which the 
Electron consults when the 
main program calls a 
procedure such as PROCinput. 
It's these procedures that do 
the work. 

When Character Shaper is 
run it reads lines 10, 20 and 
30, ignores everything after 



the REM and goes on to line 
40. This sets up the array 
byteSO and then the program 
goes on to line 50. 

Here the micro finds a 
single word, PROCinput. This 
tells the Electron to look for a 
procedure of that name, 
execute the lines that perform 
that procedure and then get on 
with the next line, line 60. 

PROCinput is defined bet- 
ween lines 80 and 150. For 
the most part it consists of a 
FOR . . . NEXT loop using the 
loop variable row. All this does 
is to accept eight numbers 
from the INPUT of line 110 
and pass each number to 
PROCbinary - of which more 
later. 

As you might guess, the 
eight numbers you supply to 
the program are the eight 
figures that give the details of 
a user-defined character to a 
VDU23 statement. 

These numbers will be 
translated into the block dia- 
gram later in the program. 

The REPEAT... UNTIL loop 
of lines 100 and 120 just 
ensures that the numbers 
entered in response to line 
1 10's prompt are in the right 
range. 




Number Row 


t 





















3 












HBE 




t 


255 




' 





This has to be from to 2 55 
- any other number has no 
relevance to a user-defined 
character. 

If the number entered is out 
of range, the loop ensures that 
it is ignored and gives you 
another chance to enter the 
correct one. 

PROCbinary is the part of 
the program that translates 
the numbers you enter into the 
symbols representing the fore- 
ground and background col- 
ours for each row. 

The procedure is defined 
between lines 210 and 270 
and consists of a FOR... NEXT 
loop which cycles eight times. 

Two parameters are passed 
to the procedure, via the 
brackets after the procedure 
name, when the main program 
calls it. 

The first is row, which as 
you might guess is the number 
of the row that the program is 
dealing with at the moment. 

The second variable, 
number, is the number follow- 
ing the VDU23 which deter- 
mines what the pattern of offs 
and ons for that row will be. 

Lines 230 and 240 just use 
MOD and DIV to convert 
number into its binary form 



and store the result in 
byteS(row). However instead 
of Os and 1 s the program uses 
apostrophes and asterisks to 
record the pattern. 

If you don't quite follow the 
maths, have a look at Mike 
Bibby's Maths Workout in the 
April and May issues of 
Electron User. 

When PROCinput has 
called PROCbinary eight 
times, we have the pattern for 
all eight rows that make up the 
user- defined characters. 
These are held in the variables 
byteS(l), byte$(2), and so on 
until byte$(8). 

All that PROCprint does is 
to display these on screen, one 
after the other, showing the 
patterns that make up that 
character. The apostrophe is 
the background colour, the 
asterisk the foreground. 

So that's how it works. Just 
try and understand one 
procedure at a time and all will 
be made clear. 

And now if you have a 
user-defined character and 
you want to see how it is made 
up, just run Character Shaper, 
enter the eight numbers that 
come after the VDU23 and 
your Electron will do the rest. 









i 


66 

90 

126 

90 
255 

66 

60 
24 






♦ 1 <t» t> M 1 <t> 

♦ i + 1 1 1 + 

111111© 
$10 1 10 10 
11111111 

10 10 

11110 

♦ Mi MM 

















Figure III: How numbers in aVDU23 relate to row patterns Figure IV: Decimal, binary and a Devil's Head 



August 1984 ELECTRON USER 43 




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The sequel to FIRIENW000, many years ago an intrepid adventurer embarked on a quest 
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knowledge of Firienwood is not required. 

FIRIENWOOD £7.48 (CASS) £10.50 (DISC) 

An evil wizard has captured the magic golden bird of paradise and imprisoned it in a 
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BLUE DRAGON £7.48 (CASS) £10.50 (DISC) 

Somewhere in a strange and dangerous land lies a fabulous treasure guarded by a fierce 
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SURVIVOR £7.48 (CASS) £10.50 (DISC) 

The year is 1910 you are sailing on a steamer bound for Borneo when there is an 
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All the games are in machine code for fast responses and are text only. Please state 
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* Joysticks may be read directly from BASIC using the ADVAL(n) function. 
PRINTER FACILITIES: 

* Provides connections for a standard Centronics-type printer. 

* Allows use of all BBC Microcomputer printer control commands. 

* Special command enables a graphics screen to be copied to any Epson dot-matrix printer. 
ADDITIONAL SPECIFICATIONS: 

* Only Acorn-approved memory locations are used, ensuring complete compatibility with any future devices 
(sideways ROM/RAM, sound expansion, speech synthesiser, disc system etc.) 

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CENTRONICS PRINTER INTERFACE - allows use of a wide 
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THE SIR ELECTRON PRINTER/AOC INTERFACE £65.95 



THE SIR ROM/RAM EXPANSION 

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Provides 1 2 extra sockets which support a variety of ROM and 

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44 ELECTRON USER August 1984 



" SE RMSWER T «ESE QUESTIONS- 



words o** 
MfiH)?nUTO 



sumn 



Ch longer ti M e)?i 9 ~ dls Pl 
How Many words will ,.« 

What is frho Z-T ^quirt?2 

s the child'.. f ir - f 



By 

NEIL GRAHAM 



r 



I 



o 




9 




SUPER-SPELL tests your 
spelling and helps you learn 
new words. 

The core of the program 
puts a word up on the 
screen for a brief time. 
Then you have to type it in, 
hopefully correctly. 

You can choose between 
words supplied by the 
program or put in your own 
words. 

You needn't stick to 
English if you don't want 
to. Just put foreign words 
in the program's DATA 
statements. 

You pick how many 
words you want to be 
tested on. After the tests 
the Electron tells you your 
score. 

One feature of the pro- 
gram is its attempt at user 
friendliness. It seeks to 
put the user at his ease by 
asking friendly questions. 

So type it in and try it 
out. It mite improof yor 
speling. 




Turn to Page 58 



August 1984 ELECTRON USER 45 



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A subscription will ensure you 
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have it delivered to you by post. 



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Yo "' electron need* 
Protecting; eds 

Pf otect your Electron 

r thour 'uxurv 
J* cover made 
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complete with these 
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Bound in attractive red pvc with 
the Electron User logo in gold 
blocking on the spine, this 
binder will hold 12 magazines 
firmly secured in 
place by metal rods, t.o.»a 



46 ELECTRON USER August 1984 




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You can also take out a 
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August 1984 ELECTRON USER 47 



o 













Castina 

o Aeency 

o 




HAVE you a favourite character you would like to see in 
this monthly feature in Electron User? 

Send your drawing of the character, together with the 

VDU23 statement, to: Shape Dictionary, Electron User, 
Europa House, 68 Chester Road, Hazel Grove, Stockport 
SK7 5NY. 












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L»*! 



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Castle 

From Robert Grantham 
(Aslockton, Notts.) 

VDU 23,239,170,255,255, 

255,119,99,119,119 
VDU 23,240,129,129,129, 

129,0,85,255,255 
VDU 23,241,85,255,255, 

255,238,198,238,238 
VDU 23,242,127,127,127, 

127,127,127,127,127 
VDU 23,243,255,255,255, 

195,195,195,195,195 
VDU 23,244,254,254,254, 

254,254,254,254,254 




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THIS month's Casting Agency 
has a holiday feeling to it. Crabs, 
tugboats, sandcastles — they're 
all shapes you might see on the 
beach during the summer. And 
while you're on your holidays, 
how about thinking up some 
characters for the autumn? 
There's Hallowe'en in October, 
Bonfire IMight in November and 
you can guess what happens in 
December . . . 



»■ *■ 



^ 



Make your games come alive with multi-coloured shapes and characters. Arcade quality 
high-speed games are yours if you have an Electron, the ability to write BASIC programs 
and GAMEMAKER 2. 



Design your own: 
Flying Ships 
Walking Men 
Chasing Monsters 
Flashing Eyes 
Beating Wings 





SPRITE MAKER 
CHARACTER MAKER 
INPUT TUPe-FlLE 
OUTPUT TAPE -FILE 



OAMEfVMCERZ 



IH3TRUCTIOKB 



Control them 
with simple 
commands, e.g. 

*GM left 1 
*GM up 1 






#Easy to use menu style 

*32 shapes each with 2 images 

*48 possible images 

♦Different sizes - max. 16 x 24 pixels 

* Naming facility for library usage 

*Tape save and re-load 



♦Simple commands from BASIC 
♦Variable movement speed 
♦Collision detection with other shapes 
♦Variable animation speed 
♦Name prompter via fl key 
♦Low memory usage 



Sprit* 



FLYER 



2nd Ew*g_M, 2 



Him KAMK 
Colu*n« 16 



SPftlTF NAKER 



RTTUHH 



CREATE ■'■AWMD 



UXCMsSET'ALTER 



rtfllH MENU 



Become an ELECTRON GAMEMAKER 2 

Send the coupon below for your copy 

Price includes postage, VAT and our guarantee. 



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1 enclose £ 

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Technical 
Advice^ 





world of the Electron and BBC Micro! 



show. So this 



home 



to give 



show it all. 





to Sunday, July 19 to 22 




Reduced prices for 
School/College Groups 

Entry only £1 per student if bookings are made in 
advance. Send your cheque (made payable to 
Database Publications) and SAE to: 

Electron & BBC Micro User Show 
68 Chester Road, Hazel Grove 
Stockport SK7 5NY Tel: 061456 8383 

Valid for a minimum oflOpeople 



SAVE MONEY with our 
Special Travel and Hotel Offer 

Visitors to the Show can obtain cut-price rail 
tickets from ANY station in the United Kingdom 
- plus special reduced prices at London hotels. 

For full details write to: 

Travel Offer, P.O. Box 1, St. Albans AL1 4ED with SAE 
or Telephone: St. Albans 34475 quoting: The Electron 
& BBC Micro User Show. 



This voucher is worth 
£1 per head 



CTR6 



BBC MICRO 



^W 7 



By handing in this voucher 
at the door you save £1 off 
the normal admission 
price of £3 (adults) and 
£2 (children). 

(Valid for a maximum of 4 people) 



10am - 6pm,Thursday,19July 
10am - 6pm, Friday, 20 July 
10am - 6pm, Saturday, 21 July 
10am - 4pm, Sunday, 22 July 

Alexandra Palace 
Wood Green, London N22. 

Number attending: [T] [Tl H^l R1 



CHESHIRE CAT 

EDUCATIONAL SERIES 

from 

AMPALSOFT 




CHESHIRE CAT 

The First name in Educational Software. 

An exciting range of top quality programs 

Available for BBC, Electron, Dragon 64, Dragon 32 
Available shortly for Commodore 64, Spectrum 48K 

RETAILER ENQUIRIES WELCOME 



Ampal Computer Services Ltd., 
31 Woodbridge Road, Darby Green, Blackwater, 

Camberiey , Surrey. 
Tel: (0252) 876677. 




*jP V 



Castles of Sand listing 



From Page 33 


L0UR3:C0L0UR130:SANDX=SANDX+ 


LEASE ENTER YOUR NAHE!!"+STR 


1660DEFPR0Ciinit 


Vr 


1 


INSt(9,CHR$32) 


1670LEVELX=1 


300VDU23,237,0,60,4,28,4,4 


750PRINTTAB(BX,AX);Nti 


1290F0RAX=1T039 


1680SX=0 


.4,0 


760PX(BX,AX)=NX 


1300PRINTTAB(AX,0);CHR*229 


1690PRINT"Hhat level? 1-3" 


310VDU23,238,0,60,36,6Q,36 


770C0L0UR128 


1310F0RA=0T0250 


1700REPEAT 


,36,60,0 


780NEXT, 


1320NEXT 


1710HX=VAL6ET$ 


320VDU23, 239, 0,60, 36, 60,4, 


790PRINTSTRINGt(40,CHR$32) 


1330S0UND1, -15, 150,1 


1720UNTILHX>0ANDHX<4 


4.4,0 


t 
1 


1340PRINTTAB(AX,0);MID$(M$, 


1730IFHX=3 HX=4 


330VDU23 , 240 , , , 48 , 76 , 135 


800COLOUR131 


AX,1);CHR$229 


1740ENDPR0C 


,3,0,0 


810PRINTSPC(20) 


1350NEXT 


1750DEFPR0Cinit 


340VDU23 ,241,0,0,110, 255 , 2 


820PR0Cbarraqe(25-LEVELX) 


1360PRINTTAB(10,3+CX*2);SPC 


1760B0NUSX=1500 


48,159,6,0 


830C0L0UR128 


(20) 


1770XX=9 


350VDU23,242,0,0,111,252,2 


840C0L0UR2 


1370INPUTTAB(10,3+CX*2)Hf(C 


1780YX=16 


40,156.15,0 


850PRINTTAB(0,29); "SCORE:" 


X) 


1790CXX=0 


360DIMPX!19,26>,WX(19),HX( 


""BONUS: BEACH:" j 


1380IFLEN(Hf(CX))>10ANDINST 


1800CYX=0 


10),Hf(101 


860PR0Cinit 


R(Ht(CX),CHR$32) H$(CX)=LEFT 


1810WPX=9 


370FORAX=OT010 


870PR0Ctext 


$(H$(CX),INSTR(HJ(CX),CHRI32 


1820XDX=0 


380HX(AX!=(10-AX)«50 


880PR0CdraH(0,0) 


))ELSEIFLEN(H$(CX))>10 HttCX 


1830YDX=-1 


390H$(AX)="Electron User"+ 


B90REPEAT 


)=LEFT$(H$(CX),10) 


1840CRX=0 


CHR$32+CHR$240+CHR*242 


900FORAX=1TOHX 


1390IFMID*(H*(CX) ,1,1)>="0" 


1850FASTX=-1 


400NEXT 


910NPX=WPX+1 


ANDHID$(HI(CX),1,1)<=*9" Ht( 


1860WXX=0 


410LE$="Z" 


920IFNPX=20 HPX=0 


CX)=Ht(VAL(HID$(Ht(CX),l,D) 


1870HYX=0 


420RI*=°X" 


930PR0Cwave 


) 


18S0H0RNX=1 


430UPt=V 


940PR0C«ove 


1400HJ(CX)=H$(CX)+CHR$32+CH 


1890WAVEX=1 


44000*="/" 


950NEXT 


R$229 


1900SOUNDO,1,5.50 


450TTt="ZX:/PSFQH" 


960PRQC«ove 


HlOPROCscores 


1910ENDPR0C 


460REPEAT 


?70PR0Cmove 


1 420REPEATUNT I LGET=32 


192ODEFPR0Ctext 


470N0DE6 


980IFRND(3)=1 B0NUSX=B0NUS 


1430IFINKEY(-2! PROCsave 


1930C0L0UR1 


480PR0Ciinit 


M 


1440REST0RE 


1940PRQCnu«(SX,6,29) 


490REPEAT 


990C0L0UR1 


1450UNTIL0 


1950PR0Cnue(BQNUSX,6,31) 


500M0DE5 


1000PR0Cnu«(B0NUSX,6,31) 


1460DATA"BSSSSSSSC5CSCSSSSS 


1960PR0Cnui(LEVELX, 17,31) 


510PR0Cc 


1010UNTILDEADX0RSANDX=0 


SB" 


1970ENDPR0C 


520VDU19, 1,3, 0,0, 0,19, 2,1, 


1020HX=HX+1 


1 470DATA"BBSSSSSSCCCCCSSSSS 


1980DEFPR0Cnum(NX,X,Y) 


0,0,0,19,3,4,0,0,0 


1030PR0Ctext 


BB" 


1990S$=STR$(NX) 


530SANDX=0 


1040IFDEADX=0 PROCrestcre 


1480DATA"BBBSSSSSCCCCCSSSSB 


2000T$=" 


540F0RAX=0TQ19 


1050UNTILDEADX 


BB" 


2010F0RL00PX=1T0LENS* 


550PX(AX,1)=1 


1060S0UNDM0.-15.4.40 


1490DATA"BBBBSSSSCCCCCSSSBB 


2020T*=T$+CHR$(ASC(MID*(Sf, 


560WX(AX)=1 


1070C0L0UR128 


BB' 


L00PX,1))+182) 


570NEXT 


1080C0L0UR3 


1500DATA"BBBBSSSSCCCCCSSSBB 


2030NEXT 


580F0RAX=0T09 


1090FORBX=0TO26 


BB" 


2040IFNX=0 T$=CHR$230 


590PX(AX,2)=1 


1100F0RAX=0T019 


1510DATA"BBBBSSSSCCCCCSSSBB 


2050PRINTTAB(X,Y)iT$; 


600WX(AX)=2 


1110PX(AX,BX)=0 


BB" 


2060IFX=6ANDY=310RX=6ANDY=2 


610NEXT 


1120PRINTTAB(AX,BX);CHR$224 


1520DEFPR0Cbarraqe(BX) 


9 PRINTSPC(l): 


620C0L0UR3 


1130NEXT, 


1530C0L0UR129 


2070ENDPR0C 


630PRINTSTRIN6*(50,CHR$224 


1140H0DE6 


1540F0RAX=0T0BX 


2080DEFPR0CHave 


)i 


U50IFSX<=HX(10) 60T01410 


1550REPEAT 


2090PRDC«or« 


640C0L0UR1 


1160CX=11 


1560XX=RND(19)-1 


2100IFHPX=0 WAVEXMHAVEX+1) 


650F0RAX=0T0350 


U70REPEAT 


1570YX=3+RND(8) 


«0D2:IFWAVEX=0 S0UND&10, 1 , 5, 


660VDU32 


1180CX=CX-1 


1580UNTILPX(XX,YX)=0ANDPX(X 


50 


670NEXT 


1190UNTILHX(CX)>SX0RCX=0 


X+l,YX)=0ANDPX(XX+l,YX+l)=0A 


2110IFMX(WPX)=26 ENDPR0C 


680F0RAX=20T025 


1200CX=CX+1 


NDPX(XX,YX+1)=0 


2120TX=PX(NPX,HX(HPX)+1) 


690READAJ 


1210F0RAX=10T0CX+1STEP-1 


1590PX(XX,YX)=3 


2130IFTX=0 HX(MPX)=HX(WPX)+ 


700FDRBX=0T019 


1220HX(AX)=HX(AX-1> 


1600PX(XX+1,YX)=3 


1:C0L0UR3:PR1NTTAB(HPX,WX(WP 


710B$=MD*(A$,8X+1,1) 


1230H$(AX)=H$(AX-1) 


1610PX(XX+1,YX+1)=3 


X));CHRt224:PX(WPX,WX(HPX))= 


720IFBf="B" N$=CHR$32:NX=3 


1240NEXT 


1620PX(XX,YX+1)=3 


1 : ENDPR0C 


:C0L0UR129 


1250HX(CX)=SX 


1630PRINTTAB(XX,YX)iSPC(2)i 


2140IFTX<30RTX>5 ENDPR0C 


730IFBt="S" N*=CHR$32:NX=0 


1260*FX12 


TAB(XX,YX+l)jSPC(2) 


2150IFLEVELXM5 NX=0 ELSENX 


: COLOUR 1 


1270PR0Cscores 
1280H»=STRINS$(7,CHR$32)+"P 


1640NEXT 
1650ENDPR0C 


h 


740IFBt="C" N*=V:NX=2:C0 


—— V 



August 1984 ELECTRON USER 53 




or don 't they e ven get off the ground? 
BRING YOURDESIGNSTO LIFE WITH 














HSfc WgB 




From head to screen, transfer your multi-coloured characters quickly and simply with 
the grid-based generator program. As you design the shapes they are automatically 
stored in our sprite routine which lies hidden under your program. You will notice the 
difference as soon as you move the character designs — our sprites move at an 
astounding fourteen (14) times the speed of ordinary Basic! 




FEATURES INCLUDE: 

Sprite Generator Programs to create your sprite 

designs. 
Upto 48 Sprites on screen - 12 separate sprite 

designs, each with 3 clones. 
Instant Animation with 2 automatically 

switching images per sprite. 
Supersprites of up to 24 x 24 pixels. 
16 colours in each sprite. 
14-Fold increase in speed over ordinary Basic. 

Built in collision detection facilities. 
Enlargement facility of x2, x3, x4, x5 
magnification of sprite size. 



Flight paths that sprites can automatically 

follow. 
A sprite library of sprite designs. 
30 Programs - choose the routine with the 

combination of features that suits your 

program best. 
Need take as little as 1.5K RAM. 
Your program SAVED/LOADED AS A WHOLE 

with sprites and sprite routines. 
Comprehensive colour manual. 
Demonstration games. 
Introduction program. 



Please rush me 



(Qty) 



SIMONSOFT SPRITES Version Two for 
the ELECTRON at £8.95 each. 

(Qty) SUPERFRUIT for the 



ELECTRON at £5,95 each. 



NAME 



ADDRESS 



Cut out this coupon and send it to: 
SIMONSOFT 25 Tatham Road, 
Abingdon, Oxon OX14 1QB. 



Please attach P.O. /Cheque 
payable to SIMONSOFT 



SUPERFRUIT at £5.95 for the Electron 



Simply the best! 

Full colour hi-res graphics, great 
sound effects, spinning reels, five 
row by four column display of fruit, 
win-line, "bounce" as each reel 
settles, nudge box. nudge gambles, 
two-way nudges, swap reels, hold 
reels, collect win. gamble any win, 
"loser's gamble" if first gamble is 
lost, Supergamble for the jackpot, 
and a coin pile that shrinks and 
grows with your winnings. 
Separate instruction program. This 
implementation is in a class of its 
own. 




SCREEN PHOTOGRAPH 



PROGRAMMERS: we pay 

lump sums and/or royalties for 
EXCELLENT PROGRAMS 



A M UST for anyone who wants to see their 
Electron's graphics stretched to the very 
limit. 



54 ELECTRON USER August 1984 



Castles of Sand listing 



From Page 53 

=15-LEVEL7. 
2160IFRND(NX)=1 P%(WPX,WX(W 

PX)+1!=TX+1 
2170IFPX(WPZ,HX(WP%>+l)=i P 

X(WPX,WX(WPXM)=1:WX(WPX)=« 
X(NPX)+1:C0L0UR3:PRINTTAB(WP 
Z.WZ(WPX) ) ;CHR$224:S0UND3,-i 
0,10,10:ENDPR0C 

2180ENDPRQC 

2190DEFPR0C«iove 

2200PR0Cdeadcheck 

2210IFDEADX ENDPRQC 

2220T$=INKEY$(0) 

2230*FX21 

2240IFINSTR(TT$,TJ)=0 G0T02 
340 

2250IFT$=LE$ PROCleft 

2260IFT$=RI* PROCright 

2270IFT$=UP* PROCup 

2280IFT*=D0$ PR0Cdonn 

2290IFT$="P" PROCpause 

2300IFT$="S" FASTX=0 ELSEIF 
Tf="F M FASTX=-1 

2310IFT$="0" THEN *FX210,1 

2320IFTI="H" THEN *FX210,0 

2330IFFASTX=0 F0RA=0TQ250:N 
EXT 

2340IFINKEY(-99)ANDYX<>26 S 
HX=l:PR0Cdig 

2350IFINKEYH) PROCfill 

2360IFINKEYI-74) SHX=-l:PRQ 
Cdiq 

2370PR0Cdeadcheck 

2380ENDPR0C 

2390DEFPR0CleU 

2400IFXX=0 ENDPRQC 

24 ! OIFPX (XX- 1 , Y%} >-l ANDP7. ( X 
X-1.YXK3 PR0Cdraw(-l,0) 

2420ENDPR0C 

2430DEFPR0Criqht 

2440IFXXM9 ENDPROC 

2450IFPX(XX+1,YX)>-1ANDPX(X 
X+1.YXK3 PR0Cdraw(l,0) 

2460ENDPR0C 

2470DEFPR0Cup 

2480IFYX=0 ENDPROC 

2490IFPZCXX,YX-1>>-1ANDPX(X 
X.YX-1K3 PROCdraw(O.-l) 

2500ENDPR0C 

2510DEFPR0Cdottn 

2520IFYX=26 ENDPROC 

2530 IFPX < XX , YX+ 1 ) >- 1 ANDPX ( X 
X.YX+1K3 PR0Cdraw(0,l> 

2540ENDPR0C 

2550DEFPR0Cdran(DX,DYX> 

2560IFPX(XX,YX)=2 C0LOUR130 



ntfHf 



.."■•■■ : : 



l*£l«Ull 



i ; [ r t ■ -VTi" K i 



*#» 



■nui^ 






09 












.:.."■'-' 



' r ' 1 "" 1. 



,t: " * : 1 1 



... ■■■•-•■ 



icevs 



Tfj 



gPflce 



lay 



Big »OW N 



ay 



P «ESS 






:C0L0UR3:PRINTTAB(XX,YX);V 
:C0L0UR128:G0T02590 

2570C0L0UR1 

2580PRINTTAB(XX,YX);SPC(1) 

2590C0L0UR2 

2600XX=XX+DX 

2610YX=YX+DYX 

2620XDX=DX 

2630YDX=DYX 

2640PRINTTAB(XX,YX);CHRt(22 
8+CRX) 

2650ENDPR0C 

2660DEFPR0Cdeadcheck 

2670IFB0NUSX<10RPX(XX,YX)=1 

DEADX=-1 ELSEDEADX=0 

2680ENDPRQC 

2690DEFPR0Cdiq 

2700DX=PXIXX,YX+SHX) 

2710IFDXO3ANDDXO6 ENDPROC 

2720IFDX=6ANDHX=4 ENDPROC 

2730IFCRX=1 ENDPROC 

2740F0RNX=0T02 

2750FORHX=OT03 

2760S0UND2,-15,50,0 

2770NEXT 

2780S0UND2,0,0,5 

2790NEXT 

2800IFDX=3 PX(XX,YX+SHX)=0: 
COLOUR 1: COLOUR 128 ELSEPXIXX, 
YX+SHX) =2: SX=SX-24 : PROCtex t : 



SANDX=SANDX+1:C0L0UR130:C0L0 

UR3 

2B10IFDX=3 PRINTTAB(XX,YX+S 

HX)iSPC(l) ELSEPRINTTAB(XX,Y 
X+SHX)jV 

2B20CRX=1 

2830C0L0UR1 

2840C0L0UR128 

2850PR0CdraN(0,0l 

2860ENDPR0C 

2870DEFPR0Cfill 

2880IFYX-1=-1 ENDPROC 

2890DX=PX(XX,YX-1) 

2900IFDXO0ANDDXO20RCRX=0 
ENDPROC 

2910SOUND2,-10,10,10 

2920IFDX=0 PX(XX,YX-1)=3 EL 
SE PX(XX,YX-1)=6:SX=SX+25:SA 
NDX=SANDX- 1 : SQUND2 ,-10,5,10: 
PROCtext 

2930CRX=0 

2940PR0CdraH(0,0) 

2950DX=PX(XX,YX-1) 

2960C0L0UR129 

2970PRINTTAB(XX,YX-1);CHR$( 
32) 

2980CDL0UR128 

2990ENDPR0C 

3000DEFPR0Cend 

3010*FX12 



3020*FX12,2 

3030REP0RT ■ 

3040PRINT" at line ";ERL 
3050END 

3060DEFPR0Crestore 
3070REST0RE1460 
3080F0RBX=0T025 
3090F0RAX=0T019 
3100PX(AX,BX)=0 
3110NEXT, 

3120LEVELX=LEVELX+1 
3130FORA=0TO255STEP0. 2 
3140S0UND1,-15,A,0 
3150S0UND2,-15,255-A,0 
3160NEXT 

3170VDU19,3,0,0,0,0 
31B0F0RAX=-15T00 
3190S0UND1, AX, 100,1 
3200S0UND1, AX, 101,1 
3210S0UND1, AX, 100,1 
3220S0UND1,AX,99,1 
3230NEXT 
3240COLOUR1 

3250F0RAX=0T0252STEP13 
3240FORBX=225T0227 
3270A$=STRING$(4,CHR$(BX))+ 
CHR*32+STRING$(5,CHR$(BX>) 
3280PR I NTTAB < 5 , 1 6 ) ; A* 



August 1984 ELECTRON USER 55 



Run rings around your screen 



with MIKE COOK'S . . . 



TH€ FA/T 



CLLipre 



10 REM (0 ELECTRON USER 

20 DAFT=FALSE 

30 REPEAT 

40 MODE 1 

50 PRINT TAB(0,15);"THE 

FAST ELLIPSE" 
40 PRINT 

70 PRINT "By Mike Cook" 
80 PR0C_H0LD 
90 MODE'o 

100 FOR 1=400 TO STEP -40 
110 PR0C_ELL I PSE £ 640 ,512 

,400,1,90,40) 
120 PROC_ELLIPSE(640,512 

,400^1,0,40) 
130 NEXT 
140 PR0C_H0LD 

150 FOR j>30 TO 250 STEP 10 
160 PR0C_ELLIPSE(i4O,5!2 
,!I+20!*2,100,I,40! 



170 
180 
190 
200 

210 

220 
230 
240 
250 
260 
270 
230 
290 

300 

310 

320 



NEXT 

PROCJOLD 

FOR [=1 TO 180 STEP 10 

PROCJLLIPSE (640,512 

,400,100,1,40) 

NEXT 

PR0C.H0LD 

UNTIL DAFT 

DEF PR0C.H0LD 

FOR A=l TO 9000 

NEXT 

CLS 

ENDPROC 

REM II, YX THE CO-ORDNATS 

OF THE CENTER 
REM MA?. THE BENI-HMflR 

AXIS 
REM RI1 THE SEMI -MINOR 

AXIS 
REM I THE INCLNATION 










\ 



■ 

V 




■ 


IN DEGREES 


450 X I =MA7.*C3 


330 REM Ht THE NUMBER OF 


460 Y1=MI7.*S3 


POINTS 


470 m*Xl+U*GMi*Sl 


340 DEF PROC ELLIPSE (XX 


480 YT7.=YX+X1*S1+Y1»C1 


,YX,MA7.,MIX,I,NX! 


490 IF AM 


350 LOCAL P,C1,S1,C2,S2 


THEN MOVE ITZ,V?J 


,C3,S3,AX,Xn,YU.,T 


ELSE DRAM XTS.YTJ 


,X1,YI 


500 T=C3*C2-S3*S2 


360 P=2»PI /(NX-1! 


510 S3=S3*C2*-C3*S2 


370 I=RAD (I! 


520 C3=T 


390 C1=CDS (!) 


530 NEXT 


390 S1=SIN (I) 


540 ENDPROC 


400 C2=CQS (P) 








410 S2=SIN !P! 




This listing is included in 




420 C3»l 




this month's cassette 




430 S3=C 




tape offer. See order 




440 FOR AM TO N?. 




form on Page 47. 




■m. ^^^b. & h ^m 







SUP IEIRIGIOIL F 



Command your own fleet! Battle plan unfolds to sea level 
view of individual engagements. 
Cannonballs smash into hulls and tear holes in sails! 
Magazines explode! Ships sink! Fire ships can be sent 

downwind ! Flags are struck and prizes taken ! £8.00 

'Trafalgar is a good combination of Arcade 
Action and Strategy — a game for the younger 
war game addict'. 

COMPUTER AND VIDEO GAMES 

The game that all the family can play! 

Amazingly realistic - the ball speeds into the air, slows, 
curves down and rolls. Bunkers, water, 0.0. B., and a 
variable gusting wind to cope with! Up to 4 player?. With- ' 

score card for each! f ..*}£7.50 

7 do know a good game when I see one and 
Supergo/f is just that'. ELECTRON USER 

'Left me wanting to play again'. MICRO USER 

60TH THESE GAMES FEATURE SUPERB MULTICOLOUR 
GRAPHICS AND ARE AVAILABLE FROM W.H. SMITHS 
AND ALL LEADING SOFTWARE SHOPS. 
OR MAIL ORDER DIRECT FROM: 

Dept E, 

4 BINDLOSS AVENUE, ECCLES, MANCHESTER M30 ODU 

24 Hour answe ring s ervice - 061-789 4120 

Cheques, P.O.s ^j| Programs required. Good royalties paid. 




*Acorn Electron 

*BBC Model/B *Tandy c/c (32K) 

*Commodore-64 "Dragon 32/64 

•Atari 400/600/800 (48K) 

747 Flight Simulator 

from DA CC - The Simulation specialists 



NOW ON 
THE ELECTRON! 



!»• 



Actual screen photograph 

Unrivalled and unbeatable for accuracy and realism - 
the DACC 747 Flight Simulator is the most successful of 
its kind on home computers. The only simulator which 
shows all the essential flight and engine instrumentation 
of the Jumbo Jet, as they really are - real dials - and with 
a precise 3D view of the runway. The control and 
response of the 747 are faithfully reproduced using 
genuine aero-dynamics formulae.- Start options include 
take-off, random landing approach, passenger and fuel 
load selection, etc. You control the throttles, elevators, 
ailerons, flaps, spoilers, landing gear, brakes, reverse 
thrust, etc. Joysticks are optional on all but Dragon and 
Tandy versions. 

Cassette £9.95 (inc. VATandP&P) 
Special Offer on Joysticks 

Normally £17.95 per pair. Yours for only £12.95 if 

ordered with 747 Simulator {Atari & CBM-64 types £14.95). 

Please state type of computer on all orders. 

WE DESPA TCH WITHIN 48 HOURS 

Order direct from: 

DA CC L td. (Dept YC2) 
23, Waver ley Road, Hindley, Nr. Wigan, 

Lanes. WN2 3BN. 



56 ELECTRON USER August 1984 



Castles of Sand listing 



From Page 55 

3290S0UND1,-15,AX+BX-224,1 
3300FORA=OT0100:NEXT 
3310NEXT, 

3320PRINTTAB(5, 16) ; "Hell Do 
ne!" 

3330S0UND1 ,-15,50, 10 
3340SX=SX+B0NUSX 
3350PR0Ctext 
3360F0Rft=0T0 10000 
3370NEXT 

3380ENDPR0C 

3390DEFPR0C5cores 

3400CLS 

3410#FX15 

3420PRINTSPC(3)"T D A Y ' 

S";SPC(3);"G R E A T E S T 



f t 



3430FORAX=1T010 

3440PRINTTAB(0,3+AX*2);HX(A 

?.)i" ";TAB(10,3+AX* 

2);Ht(AX);SPC(20); 

3450NEXT 

3460ENDPR0C 

347QDEFPR0Cpause 

3480F0RA=0T0100 

3490NEXT 

3500REPEATUNTILGETt="P" 

3510ENDPR0C 

3520DEFPR0Csave 

3530CLS 

3540PRINT"Do you want to Lo 
ad or Save? L/S" 

3550REPEATSt=GETt 

35A0UNTIL6M"L"0R6t="S" 

3570PRINT"Put the tape in t 
he right place. "'"Then press 

space." 

3580IFGt="L" GOTQ3670 

3590REPEATUNTIL6ET=32 

3600FX=0PEN0UT(*H. SCO. SAND" 



3610F0RAX=0T09 
3620PRINTIFZ,HZ(AZ),H*1AZ1 
3630NEXT 
3640CL0SE#F% 
3650VDU7 
3660ENDPROC 

3670FZ-0PENIN 1 "H. SCO. SAMD" ) 
3680F0RAX=0T09 
3690INPUTIFZ,HZ(AZ),H*(AZ) 
3700NEXT 
3710CL0SEIFX 
3720VDU7 
3730ENDPR0C 
3740DEFPR0Cwor« 
3750IFWXX=0ANDWYX=0ANDRND ( 1 
00)01 ENDPRDC 



3760IFWXX=OANDWYX=0 WYZ=12+ 
RND(4):IFPZ(0,WYZ)O00RPZ(l, 
WYX)<>00RPZ(2,WYZ)O00RPX<3, 
WYX1O0 ENDPRDC 

3770IFWQRMX=0ANDRND(2)=1 WX 
X=WXX+1 

37S0IFWXX=17 PRINTTAB!WXX,H 
YX);SPC(3):PR0Cfillup:WXX=0: 
WYX=0:ENDPROC 

3790W0RNXMW0RMX+DM0D2 

3800Wt=CHRt240+CHRt(241+W0R 

m 

3810C0L0UR2 
3B20PRINTTABtWXX,WYX);SPC(t 

MM 

3830IFPZ(WXZ,WYZ)=t CDL0UR3 
:PRINTTAB(WXX,WYX);CHRt224 

3840IFXX>WXX-1ANDXX<WXX+4AN 
DYX=WYX B0NUSX=B0NUSX-2:CRX= 



3850IFXX>WXX-1ANDXX<WXX+4AN 
DYX=WYZ 

3860IFPZ(WXX+3,WYX)O0ANDPX 
(WXX+3,WYXK>1 60T03880 

3B70ENDPR0C 

3880IFPX(WXX+3,WYX)<>3 PRIN 
TTAB(WXZ+1,WYX);SPC(2):WXX=0 
:WYX=0: ENDPRDC 

3890PX(WXX+3,WYX)=0 

3900PRINTTAB(WXX,NYX!;SPC<4 

! 

3910WXX=0 

3920WYX=0 

3930ENDPR0C 

3940DEFPR0Cf illup 

3950C0L0UR3 

3960F0RZX=WXXT019 

3970IFPX(ZX,WYX)=1 PR1NTTAB 
(ZX,WYX);CHRt224 

3980NEXT 

3990ENDPR0C 
' 4000DATA"NFFFFLFFSSSSFFBBLM 
LLLSSSSBLLFFMLTFSSSSBTBBRMLL 
RSSSSBLFBFHFFFSSSSFLNN" 

4010DATA"SFFF0SSSSFFFFSSSSL 
BBBSSSSLBBBSSSSFFBBSSSSFFBBS 
SSSRBBBSSSSRBBBSSSSFBBFSSSSF 
BBO" 

4020DEFPR0Ctitles 

4030Ft=CHRt224 

4040SI=CHRI32 

4050RESTORE4000 

4060CLS 

4070READA* 

408OF0RAX=lTOLENAt 

4090Bt=MIDt(At,AX,l) 

4100IFBt="S" PRINTS!; 

4110IFBt="F" PRINTSt;Ft;Ft; 
Ft; 



4120IFBf="L" PRINTS!;F!;St; 
St; 
4130IFBt="R" PRINTSI;Sf;St; 

Ft; 

4140!FBI="B" PRINTSt;Ft;St; 
Ft; 
4150IFBt="T" PRINTSt;Ft;Ft; 
St; 

4160IFBt="M" PRINTSt;St;Ft; 
St; 

4170IFBt="N" PRINT 
41S0NEXT 
4190READAt 
4200F0RAX=lT0LENAt 
4210Bt=MIDt(At,AX,l) 
4220IFBt="S' PRINTSt;St; 
4230IFBt="F" PRINTSt;St;Ft; 
Ft;Ft;Ft;Ft;Ft; 
4240IFB!="l" PRINTSt;St;Ft; 
Ft;St;3t;St;St; 

4250IFBt="R" PRINTSt;St;St; 
St;St;St;Ft;Ft; 

4260IFBt="B" PRINTSt;St;Ft; 
Ft;St;St;Ft;Ft; 

4270IFB!="T" PRINTSf;St;Ft; 
Ft;Ft;Ft;St;St; 

4280IFBf="0" PRINTSt;St;Ft; 
Ft;Ft;Ft;Ft;St; 

4290IFBt="M" PRINT3t;St;St; 
St;Ft;Ft;St;St; 

4300IFBt="N" PRINT 

4310NEXT 

4320PRINT TAB(18!;"By"' 

"TAB(12); "Martin Hollis" 

4330PR0Cspc 

4340ENDPR0C 

4350DEFPR0Cspc 

4360PRINT"SPC!8); "PRESS SF 
ACE TO CONTINUE" 

4370REPEAT 

4380UNTILGET=32 

4390CLS 

4400ENDPR0C 

4410DEFPROCinstr 

4420PRINT""The abject of t 
he gaue is to fill in" '"the 
sand castle with sand from t 
he" "beach. The sea is advan 
cinq slowly" "towards the bo 
tton of the screen. "'"Any sa 
nd it aeets is slowly washed 
"'"away but don't worry, the 

sea can't" 

4430PRINT*eat your castle - 

but it will wash" '"away any 

other sand it aeets!"'"You 

must position the san above 

or" '"below the sand you wan 
t to dig and" "then pick it 



up in your bucket. When"'"yo 
u drop the sand it fills in 
the" 

4440PRINT"block directly ab 
ove you. Everytine"'"you fil 
1 in a block of the castle"' 
"you score 25 points." 

4450PR0Cspc 

4460PRINT' '"When you've use 
d all the sand at" "each sid 
e you can collect lore froa." 
'"the top of the screen but 
beware the" "hungry sandwort 

crossing your path ! " * "If he 

catches you when your bucke 
t is" 

4470PRINT"full he will eat 
your sand. However" "you are 

still alive to dig for more 
."""You can only die if the 

sea drowns" '"you or if your 

bonus falls tc zero. When 

you die the Hiscore Table i 

s" 

4480PRINT"di splayed. If you 

wish to SAVE the" "Hiscore 
Table for another day"'"PRES 
S (CTRL SPACE). " 

4490PR0Cspc 

4500PRI NTTAB (18,2) "KEYS " 

4510F0RAZMT010 

4520READLt,«t 

4530PRINTTAB(10,AX!;lt;TABi 
19,AX);"-";TAB!23,AX);Wt 

4540NEXT 

4550PRINT'STRINGt!10,CHRt32 
+"**"+CHRf32) 

4560PRINTSPC(3); "These keys 

aay be used during play." 

4570F0RAX=15TD19 

4580READLt,Wt 

4590PRINTTAB(10,AX);Lt;TAB( 
19,AX!;"-";TAB!23,AX);Wt 

4600NEXT 

4A10PR0Cspc 

4620ENDPR0C 

4630DATAZ, LEFT, X, RIGHT,*, UP 
,?, DOWN, SPACE, DIG DOWN,RETUR 
N.DIG ABOVE, SHIFT, FILL ABOVE 
,P, PAUSE, F, FAST, S, SLOW, Q.SIL 
ENT, W.SOUND 

4640DEFPR0CC 

4650VDU23;8202;0;0;0; 

4660ENDPR0C 



This listing is included in 
this month's cassette 
tape offer. See order 
form on Page 47. 



August 1984 ELECTRON USER 57 





I Super Spell listing 






■ 


From Page 45 






* 




11 1 " 










that." 


*a# 

10 REH mmmmmm* 




This listing was prod 
formatter which breaks 


uced using a special 
one program line over 




ELSE PRINT •Oh.I'i 

ii i iiii 


IftHtl 




several lines of listing. When entering a line don't 




very sad to hear that! 

ati 


20 REM " ♦* 




press Return until you 


come to the next line 




■ 


30 REN ** Super-Spell 

♦* 

40 REH t* by N.6rahaa 




number. Full details of the formatter are given on 




750 PRINT "Oh well, lets 




Page 4 of the February i 


ssue. 




get on with the quiz." 










760 PRINT "Press any key 


ft 


THEN SOTO 290 


570 FOR A=l TO nuaber 


to begin." 


50 REN *« ** 


310 INPUT "Hon lany words 


580 READ word* (A) 


770 LET A=6ET 


56 REN ** H 


Hill you require" 


:IF word* (nuaber )= 


780 ENDPROC 


60 REN M For ELECTRON 


,nuiber 


"t»" 


790 DEF PROCtest 


User(C) »• 


320 IF nuaber < 1 


THEN RESTORE 600 


800 VDU 19,7,3,0,0,0 


70 REN i* *t 


THEN 60T0 310 


590 NEXT A 


810 CLS 


80 REN HflffHMHtfMHHM 


330 INPUT "What is the 


600 DATA ACCEPT, CEREAL 


820 PRINT " 


90 NODE 6 


child's first naae" 


.EXPENSE, LILIES, PNEUHAT 


";prog$ 


.-REM tPUT IT IN NODE 


, childt 


IC, SKILFUL, ACCIDENTALLY 


830 PRINT " 


61 


340 IF «hich$="AUT0" 


,CEREH0NY,EXPLANATI0N 


WWW****** 


100 PROCinit 


OR nhich$="auto" 


.LITERATURE, POISONOUS 


840 FOR A=l TO nuaber 


110 PROCscreen 


THEN PROCdata 


.SOLICITOR 


850 PRINT "Type the word.. 


120 PROCtest 


350 IF which*="AUTO" 


610 DATA ACCOHH0DATION 


* 
■ 1 


130 PROCiessage 


OR «hich*="auto" 


.CHANGEABLE, EXTRAVAGANT 


860 PRINT word*(A) 


140 PROCend 


THEN BOTO 440 


.POSSESSED, SPEECH 


870 FOR liait=l TO (teapo*5 


150 END 


360 PRINT "Now type in 


,ACHE,CH0QSE,EXTREHELY 


00) 


160 DEF PROCinit 


all the words you 


.PREFERRED, STONY, AC9UA I 


880 NEXT liait 


170 REH -=-=-= ON ERROR 


require." 


NTANCE, CHOSE 


890 PRINT TAB10.4)" 


60T0 ERL =-=-= 


370 DIN word* (nuaber) 


620 DATA FASCINATIN6,L0VABL 


■ 


175 apointer=630 


380 DIN specialf(nuiber) 


E , PREPAR AT I ON , SUCCESFUL 


900 PRINT "NOW!" 


ISO nuaber=l 


390 FOR A=l TO nuiber 


.ACROSS, COCONUT, FEBRUAR 


910 PRINT '" 


190 teapo=0 


400 INPUT "Mord ",word*(A) 


Y.HAINTENANCE, PRINCIPAL 


920 INPUT answer! 


200 CLS 


410 B=LEN (word* (A) ) 


LY, "SURELY" 


930 IF answer *<>word* (A) 


210 VDU 19,1,2,0,0,0 


420 IF B<2 


630 DATA RHYHE.PAID, PEASANT 


THEN PRINT "NRONBlIt 


220 LET prog*=*SUPER SPELL* 


THEN PRINT "Error. Try 


.REHEHBRANCE.ACCASION 


should have been "jwor 


230 PRINT " 

■ 


again." 


.RE6ARD, NINETEEN, HETAPH 


df(A) 


";prog$ 


:60T0 400 


OR, BURIED.GUARD, OBLIGE 


:LET special$(A)="NR0N6 


240 PRINT " 


430 NEXT A 


, DISGUST, PARLIANENT 


ii 


*************** 


440 CLS 


."NINIATURE" 


.•SOUND 1,-15,1,5 


250 PRINT '"This is for 


450 SOUND 1,-10,100,10 


640 DATA GRANHAR.RIPE 


ELSE PRINT "CORRECT iVer 


PARENT/SUPERVISOR." 


.'SOUND 1,-10,200,5 


, SATELLITE, HALLABY 


y good ";child* 


260 PRINT "PLEASE ANSWER 


460 PRINT "Thank you very 


.YACHT.PIGEON.NOUSTACHE 


:correct=correct+l 


THESE QUESTIONS! ' 


auch. Press any key 


.VEHICLE, DISAPEAR 


:speciall(A)s"C0RRECT!" 


270 INPUT "Do you want 


to begin the test." 


.EVAPOURATE.FULFILED 


.•SOUND 1,-15,200,5 


to enter your own 


470 corrects 


,'PERFORHANCE","**' 


940 PRINT "PRESS ANY KEY 


words or use the 


480 LET A=SET 


650 ENDPROC 


TO CONTINUE" 


pre-set ones (AUTO 


490 ENDPROC 


660 DEF PROCscreen 


950 B=SET 


or HAN)", which* 


500 DEF PROCdata 


670 CLS 


960 CLS 


280 IF «hich$="AUT0" 


510 line=RND(7) 


680 VDU 19.7,1,0,0,0 


970 PRINT " 


OR «hich*="auto" 


520 lineb=INT (line) 


690 PRINT " 


•;prog$ 


OR which$="HAN" 


530 IF lineb=-l 


*iprog$ 


980 PRINT " \ 


OR which$="aan" 


THEN LET apointer=600 


700 PRINT ' 


************ 


THEN SOTO 290 


:IF lineb-1 OR lineb=2 


%*******%**l 


990 NEXT A 


ELSE GOTO 270 


OR 1 ineb=0 


710 PRINT "Hello, "jchild$: 


1000 VDU 19,7,4,0,0,0 


290 INPUT "Please enter 


THEN LET apointer=610 


*, are you all right 


1010 ENDPROC 


tiae delay (1-displaye 


535 IF lineb=3 OR lined =4 


"i 


1020 DEF PROCaessage 


d only for a very 


THEN LET apointer*620 


720 INPUT a* 


1030 CLS 


short tiae TO 9-displa 


:IF lineb=5 OR lineb=6 


730 PRINT 


1040 PRINT " 


- ed for a iuch longer 


THEN LET apointer*630 


740 IF a**"YES" OR a*= 


"iprogt 


tiie) " ,te«po 


538 RESTORE apointer 


■Y* 


1050 PRINT " 


300 IF teipo <1 OR teapo 


550 DIN HordS(nuaber) 


THEN PRINT "6ood.I'a 


************ 


>9 


560 DIN special! (nuaber ) 


very glad to hear 


1060 PRINT "Nell "jchildJ; 



58 ELECTRON USER August 1 984 



" you scored" 

1070 PRINT 'correct!" out 
of "jnuiber 

1080 PRINT "Do you think 
this score is good 
or bad' 

1090 INPUT thought* 

1100 IF thought! ="S00D" 
OR thought* ="good" 
OR thought* ="BAD" 
OR thoughU^bad" 
THEN SOTO 1110 
ELSE 60T0 1030 

1110 INPUT "Did you enjoy 
it", enjoy* 

1120 IF enjoy*='YES" 
OR enjoyJ^Y 1 . 
THEN PRINT "Sood.I'i 
glad about that.* 
ELSE PRINT "Oh.I'a 
sorry. I '11 try harder 
next tite!" 

1130 PRINT "AnyNay it is 
time for ie to see 
your parent or 
teacher so GOODBYE 



■jchild*}" hope I 
see you again soon!" 
1140 INPUT '"PRESS <RETURN> 
WHEN HE OR SHE COHES'A 

* 

1150 ENDPROC 

1160 DEF PROCend 

1170 CLS 

1180 VDU 19,7,2,0,0,0 

1190 PRINT " 

";prog* 
1200 PRINT " 



1210 



1220 



1230 



1240 
1250 

1260 



PRINT 'child*;" got 
"5 correct;" out of 
"inuiber;" at SUPER-SP 

ELL" 

PRINT "In his opinion 
he »as "; thought* 

PRINT "THESE MERE 
THE WORDS HE WAS TESTE 

D ON:' 

PRINT 

FOR A=l TO nuiber 

PRINT SPC (12)!«ord*(A) 

;TAB(30);speciaI*(A) 



1270 NEXT A 

1280 PRINT "PRESS SPACE 

BAR TO CONTINUE" 
1290 REPEAT 
:A=6ET 
■ : UNTIL A«32 
1300 CLS 
1310 PRINT " 

■;progt 
1320 PRINT " 

I 

1330 PRINT "Do you wish 
to re-run this prograe 

"; 

1340 INPUT A* 

1350 IF A*="Y" OR A*="YES" 

THEN RUN 
1360 INPUT "Are you sure 

(Y/N) "A* 
1370 IF A*="N" OR A*="N0" 

THEN RUN 
1380 REN ******************* 
1390 REN »* ** 
1400 REN H SELF DESTRUCT " 
1410 REN *» «* 
1420 REN ******************* 



1430 PRINT ""I ii no* 'self 
destructing' there 
Mill be no tract 
of ie in Hiory" 

1435 FOR delay=l TO 500 

:NEXT delay 
1440 CLEAR 

:N0DE 6 
1450 m 138,0,78 
1460 *FX 138,0,69 
1470 *FX 138,0,87 
1480 *FX 138,0,13 
1490 REM ft***************** 

1500 REH ** *» 

1510 REN »» THE END »» 

1520 REN ** ** 

1530 REH ******************* 

1540 END 
(END 
:END 



This listing is included in 
this month's cassette 
tape offer. See order 
form on Page 47. 




Tutorial Software Ltd. 



SENIOR SCHOOL 
EDUCATIONAL PROGRAMS 

■ 

Developed in schools and now available to interested home 
micro users. Research has identified the compulsory exam 
topics, and professional programmers have coded these into 
exciting educational games which have been proven to 
effectively teach and entertain. 

Now available for BBC B and ELECTRON. Each pack 
contains main program, extra self test program and Core 
Facts book for only £11.95 or any two for £19.95. 



MATHS 1: 
TRY-ANGLES 

MATHS 2: 
COORDINATES 

PHYSICS 1: 
OHM RUN: 

PHYSICS 2: 
ISAAC 

GEOGRAPHY 1: 
MAYDAY 

GEOGRAPHY 2: 
WEATHER 



Draughts style teaches angles 
ratios, tan, sin, cos. 25 levels 

Battleship style teaches x and y in 
four sectors, directed numbers 

Baseball style teaches D.C. cricuits, 
resistors, ceils, V=IR, series and parallel. 

Gunnery style teaches mass, 
weight Newtons Laws and 
projectiles 

Orienteering style teaches O.S. 
symbols, grid references, bearings 

Forecasting style teaches symbols, 
pressure systems, synoptic charts 



Send your name, address, and cheque/P.O. to DEPT. E. 
TUTORIAL SOFTWARE LTD., FREEPOST, WIRRAL, MERSEYSIDE L61 1AB. 

Please state BBC B or ELECTRON 



ELECTRON 
EDUCATIONAL SOFTWARE 

Our educational software is used in thousands of schools and 
homes throughout Great Britain. Now available on Electron. 
EDUCATIONAL1 £8.00 

Hours of fun and learning for children aged 5 to 9 years. Animated 
graphics will encourage children to enjoy maths, counting, spelling 
and telling the time. The tape includes MATH1, MATH2, 
CUBECOUNT. SHAPES, SPELL and CLOCK. 
. . . 'An excellent mixture of games' . . . 

Personal Software -Autumn 1983. 

EDUCATIONAL2 £800 

Although similar to Educational 1 this tape is more advanced and 
aimed at 7 to 12 year olds. The tape includes MATH1, MATH2, 
AREA, MEMORY, CUBECOUNT and SPELL. 

FUN WITH NUMBERS £8.00 

This program will teach and test basic counting, addition and 
subtraction to 4 to 7 years olds. The tape includes COUNT, ADD, 
SUBTRACT and ROCKET MATHS an arcade type game to 
exercise addition and subtraction. With sound and visual effects. 

FUN WITH WORDS £8.00 

Start your fun with alphabet puzzle, continue your play with 
VOWELS, learn the difference between THERE and THEIR, have 
games with SUFFIXES and reward yourself with a game of 
HANGMAN. Complete with sound and graphics. The tape includes 
ALPHA, VOWELS, THERE, SUFFIXES and HANGMAN. 
. . . 'Very good indeed' . . . A&B Computing - Jan/Feb 1984. 

JIGSAW AND SLIDING PUZZLES £7.95 

There are 2 jigsaws and 4 sliding puzzles on a 3 x 3 and 4x4 grid. 
Each program starts off at an easy level to ensure initial success but 
gradually becomes harder. It helps children to develop spatial 
imagination and in problem solving. The tape includes 6 programs: 
OBLONG, JIGSAW, HOUSE, NUMBERS, CLOWN and LETTERS. 

**« SPECIAL OFFER ** # 

Buy three cassettes and deduct C4.00 

Add 50p per order p&p. Cheque to: 

GOLEM LTD, 



Dept E,77 Qualitas, Bracknell, Berks RG12 4QG. 

Tel. (0344) 50720 

For full catalogue write to the above address. 



August 1984 ELECTRON USER 59 



MOTF IMVAOFRS 

NOTE INVADERS 




* 



FOR ACORN ELECTRON 



NOTE INVADERS is an excellent way to learn the notes on the 
musical staff. A note travels across the staff and you must press the correct 
key for that note (A to G) to release your missile before the note wipes you 
out! A great game— you have 4 lives, and you can choose TREBLE or BASS 
clefs, and 3 levels of difficulty. High scores are shown. Two other programs 
are on the tape which teach and test the same skills in a more relaxed 
format. 

Age range- suitable for children AND adults-in fact for anyone learning on 
an instrument 



AVAILABLE? 

PRICE? 

PACKAGING? 

BOOKLET? 




NOW for Electron (and for BBC disc and cassette, 
Spectrum 48k and VIC 20). 
£9.95 (including VAT) 
f De-luxe plastic wallet. 
Inside. 

Available by mail order from CHALKSOFT LIMITED 

37 Willowslea Road 

or from you local dealer. WORCESTER 

WR3 7QP 

^ U Telephone 0905 55192 

Members of the Computer Trade Association. 
Telex: 339636 HEENAN-G 



ADVERTISERS INDEX 

Brother 13 

Chalksoft 60 

Cheshire Cat 52 

Computer Marketplace 16 

DACC 56 

Dialsoft 60 

Epic Software 20 

Firefly Software 4 

First Byte Computers 63 

Golem ; ... 59 

Haystack Peripherals 60 

Holly Computers 49 

J. P. Magnetics 60 

Key-Ess 30 

Kosmos 15 

Lifelong Learning 60 

Mayfair Micros 44 

M. P. Software Services 44 

Mushroom Computers 2 

Micropower 64 

National Micro Centres 22,23 

Optima Software 40 

Sir Computers 44 

Simonsoft 54 

SquirrelSoft 56 

Tutorial Software 59 



(r 



DIALSOFT 

EDUCATIONAL PROGRAMS, 

GAMES & UTILITIES, 

FOR ELECTRON & BBC. 

See reviews this Month. 

Our complete range of software has 
now been converted to operate on the 

ELECTRON. 

Send an SAE to obtain our latest 
Brochure and price list. 

DIALSOFT, 72 Downend Road, 
Downend, Bristol BS16 5UE. 



J. P. MAGNETICS LIMITED 

HAVINGTROUBLE OBTAINING QUALITY 
COMPUTER LENGTH CASSETTES? 

WE CAN SOLVE YOUR PROBLEM 

10 x C15 for £4.50 + 50p P&P 

(CASH WITH ORDER) 

We are specialists in the supply of bulk custom 
wound audio/computer cassettes. 

Trade and Educational Enquiries Welcome. 

Competitive Rates - Price List Available. 

Contact us now: (0274) 731651 

Unit 4,-7 Mary Street, Bradford, BD4 8SW. 




Step by Step 

BASIC 



«*> 



S&-.-C- 






-< 



.s*% 



tZ*4 



And to the bugs and the spaghetti! 
With Step by Step BASIC you 
learn to write well-structured 
programs from day 1 . Programs 
that work and that you can see will 
work. Colour, sound, graphics, 
files, sorting all included. 

BBC/Electron edition (203 pp) £5.95 1 
BBC/Electron program tape £5.50 
ZX Spectrum edition (177 pp) £5.95 
ZX Spectrum program tape £5.50 

LIFELONG LEARNING LTD, 
Dept EU, 55 MILTON ROAD, 
CAMBRIDGE CB4 1XA 



C15 

COMPUTER CASS 

35p 

Box of 10. . .£3.50 + £1 p&p 
Cheques, P.O/s to: 

HAYSTACK PERIPHERALS 
5 Church Road, 
Greenfield, 
Oldham OL3 7LQ. 

Educational and Dealer Enquiries Welcome 



60 ELECTRON USER August 1984 



DUE to further development 
work, owners of the First Byte 
Joystick interface can now use 
it with all Acornsoft games and 
any others that have an 
analogue joystick option, as 
well as games that use only 
keys. 

The program listed here 
should be very carefully 
entered on the Electron, but 
please save it before you run. 

Once the routine has been 
run it will stay in the machine, 
even if the Break key is 
pressed. All you then do is load 
up the game as normal and 
choose the joystick option. 

We have tried the routine 
on all presently available 
games with an analogue 
joystick option and have so far 
had a WO per cent success 
rate. This now means the 
interface works on 99 per cent 
of games on the market. - Ray 
Threadgould, FBC Sys- 
tems, Derby. 

Sanyo saves 
first time 

IN response to M. Senior's 
letter in the June edition of 
Electron User, I bought a 
Sanyo DR101 Data Recorder 
with a seven pin DIN lead from 
my local Curry's for £32.95. 

This was £10 cheaper than 
the same model at my local 
computer shop. It always 
saves first time. - Andy 
Conway, Cheltenham, 
Gloucestershire. 

Sound advice 
from dealer 

/ BOUGHT a Lloytron V171 on 
the advice of a local computer 
dealer for £24.95. 

This, along with a seven 
DIN to split microphone, 
earphone, remote lead- for an 
extra £3 - has worked 
perfectly. It's important that 
the earphone and microphone 
leads are not put in the wrong 
sockets. 

Having established which 



Micro Messages 

Joy for First Byte 
interface owners ! 



1 REM Title :FBC fid 


l&5:BCS X 


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was which, I marked them to 
avoid future confusion and 
since I found the optimum 
volume level - a quarter of its 
full potential - I've had no 
problems at all. - Yvonne 
Wilkin, Alveley, Shrop- 
shire. 

Expensive, 
but worth it 

AFTER initially trying various 
recorders that were unsatis- 
factory I have now settled for a 
Sony TCM 737. 

A /though a little more expen- 
sive than some recorders, 
this machine does seem to 
both load and save perfectly 
virtually every time. 

I hope this information may 
be of use to other Electron 
owners. - H.E. Pressey, 
Wolverhamption. 

Not lost 
a minute 

AFTER initial problems with an 
old recorder we bought a CR 



375 from Boots. This has a 
counter and easily operated 
volume and tone controls. 

We haven't lost a minute's 
computing time due to difficul- 
ties with loading and saving 
since. It does both functions 
perfectly. — Mrs N. Judge, 
Buxton, Derbyshire. 

Magic of 
Superscope 

THE cassette recorder I 
recommend is Superscope, 
available from Boots and the 
other High Street shops, 
ft costs about £38 and 



saves and loads like magic on 
the automatic recording level. 
I've had no problems with it at 
all. Brian Brown, 

Worksop, Notts. 

Trouble free 



Ferguson 



MY son has had an Electron for 
nearly two months and loading 
and saving has been consis- 
tently trouble free. My recor- 
der is the Ferguson Model 
3T07 and I have the volume 
set at approximately three 



WHA T would you like to 


tear yourself away from 


see in future issues of 


your Electron keyboard 


Electron User? 


and drop us a line. 


What tips have you 
picked up that could 


The address is: 


help other readers? 


Micro Messages 


Now's here is your 


Electron User 


opportunity to share 


Europa House 


your experiences. 


68 Chester Road 


Remember that these 


Hazel Grove 


are the pages that you 


Stockport 


write yourselves. So 


SK7 5 NY. 



August 1984 ELECTRON USER 61 



Micro Messages 



From Page 6 1 

quarters of its maximum. — 
K.R. Towers, Preston, 
Lanes. 

Timely 
praise 

/ WOULD like to recommend 
my recorder. It works with my 
Electron and has also worked 
with a ZX81, Spectrum, and 
Oric. 

It is a Wa/tam W1 74 clock 
radio cassette recorder at 
about £36. - Neil Olner, 
Thome, Doncaster. 

• Thank you to everyone 
who's written in telling us 
which cassette recorders work 
with the Electron. Here at 
Electron User we use a Pye 
audio data recorder D6600/ 
35P. We get tapes in all sorts 
of conditions and at all 
recording levels and the Pye 
recorder does a great job. 

Code breaking 
with the family 

FIRSTLY, may I congratulate 
R.A. Waddilove on his excel- 
lent program "Code Breaker", 

The only problem is, once 
you have started breaking a 
code, everybody in the house 
feels the necessity to offer 
expert advice on what the next 
guess should be! 

To make life easier, I've 
written a few extra lines to 
give each line of guesses a 
number. 

At least now you'll know 



which line your committee of 
experts is referring to, when 
they make comparisons and 
eliminations. 

All you do is delete line 760 
and add the following: 



105 PROCnunbers 

107 VDU4 

690 HOVE 0,i:DRftW 1160, i 

710 HOVE 0,96:DRAW 1160,9 
6 

730 HOVE 0,96: DRAW 0,976 
1860 DEFPRGCnumbers 
1870 COLOUR 7 
1880 VDU5:H0VE 80,255 
1890 FOR yW TO 12 
1900 IF yZ>=10 THEN PLOT 
,-64,0 

1910 PRINT;yX; 
1920 PLOT 0,-60,64 
1930 NEXT yX 
1940 SOUND 1,-15,50,5 
1950 ENDPR0C 



- Tony Farmer, Ditton, 
Kent. 

• Many thanks for the addi- 
tional lines, Mr Farmer. They 
really do help, though, of 
course, here at Electron User 
we're all too busy to play 
games! 

Not just 
flung together 

JUST out of curiosity I decided 
to solve the illustration 
accompanying Roland Wad- 
di/ove's "Crack the code!" in 
the June issue of Electron 
User. 

The solution is possible 
from the illustration (red, blue, 



green, red, red) and it just goes 
to show that these articles 
aren't just flung together but 
obviously somebody has taken 
some care in printing an actual 
game to accompany the text. - 
Nigel Shelton, Gt. Yar- 
mouth, Norfolk. 

Mysterious 
assembler . . . 

/ HAVE read somewhere in 
your excellent magazine that 
my Electron has a built-in 
assembler. How do I use it, 
and what does it do?- Robert 
Treu, Hastings. 

• The assembler is a program 
that lives inside the operating 
system of the Electron and 
allows you to speak to the 
micro in its own language, 
machine code. 

As for how to use it, we plan 
to run a series on machine 
code. If you can't wait then 
you might try the following 
books: 

Assembly Language on the 
Electron, by Ferguson and 
Shaw, published by Addison 
Wesley. 

Electron Assembly Lan- 
guage, by Bruce Smith, pub- 
lished by Shiva. 

Electron Machine Code for 
Beginners, by Ian Sinclair, 
published by Granada. 

Improve your 
character! 

FIRST of all I'd like to thank 
you for a magazine that covers 
the WHOLE spectrum (ahem) 



of uses for an excellent 
machine. 

Secondly, a/though I found 
your character definer pro- 
gram (Page 44, March issue) 
to be of great help, I 
sometimes felt the need to 
have the ability to save and 
load character sets. 

This facility can be obtained 
by adding the following lines: 



193 IF G$= n S u THEN M0DE6: 
PRQCSV : MODE 1 : PRQCSCREENPLQT 

195 IF BNV THEN K0DE6: 
PR0CLD: M0DE1 : PR0CSCREEMPL0T 

935 PRINT TAB(2,17! H To 5 
ave a character set press 



u 



937 PRINT TABC2.1?) "To 1 
oad a character set press ' 
L" 
1030 DEFPR0CSV 
1040 PRINT;PRINT:PRINT 
1050 *SAVE CHAR 0C00 0CF1 
1060 PRINT "Press any key 
to continue":Gt=GET$ 
1070 ENDPROC 
1080 DEFPR0CLD 

1090 PRINT TAMO, 10) 'Pleas 

e position the character fi 

le" 

1100 *L0AD "CHAR" 0C00 
1110 PRINT-Press any key t 

o continue" :6*=GET* 
1120 ENDPROC 



- Simon Martin, Halifax. 

• Many thanks for the listing 
which adds a new dimension 
to the program. It's always 
nice to hear from readers who 
have improved or adapted our 
programs. 




62 ELECTRON USER August 1984 






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ELECTRON JOYSTICK INTERFACE 

Electron users! This is the addon everyone wants. \m \m new 
Electron switched joystick interface from First Byte - available now 
with free conversion tape that vastly extends your game range right away. 

The interface operates with all 'Atari-style' 9-pin joysticks, and its many 
advanced design features put it way out in front for quality and reliability. 
That's why, to date 15 major software houses are already bringing out 
games that work directly with the First Byte Electron Joystick Interface 
and many more are sure to follow. 

FREE conversion tape ■ play all these to p g ames ri g ht now 

Every Electron Joystick Interface comes with a free conversion tape, 
so you can use some of the most popular games around right now: 



Look at these advanced design features. 



Works with all 'Atari- 
style' 9-pin joysticks 
and utilises rapid-fire 
mode on 
Quickshot 2, 



Only 2 chips for ultra- 
high reliability and low 
power consumption 
ensuring safe 
operation with 
the Electron. 



• Killer Gorilla 


• Kamaka2i 




• Lunar Rescue 




• Moonratder 


• Chuckie Egg 




• Bugblaster 




• Positron 


• Atom Smasher 




• Blagger 

• Bed Bugs 




• Croaker 


• Alien Break In 






• Swoop 


• Birds of Prey 




• Alien Dropout 




• Bandits at 3 o clock 


• Galaxy Wars 




• Daredevil Dennis 




• Escape from 


• City Defence 




• Snooker 




Moonbase Alpha 


• Monsters 




• Diamond Mine 




• Cybertron Mission 


• Pool 




• Vortex 




• Cylon Attack 


• Pengwyn 








The conversion tape 


also allows you to configu 


re most other games for 




joystick control. 












Custom-built 
colour- 
co-ordinated case 
in high-impact plastic 
Special fitments ensure 
lhat when the joystick is 
plugged in, the case takes th£ 
strain, not the soldered joints. 



Gold-plated 
connectors ensure a 
perfect contact. 
Metal polarising key 
and nylon end caps 
ensure positive locking. 



Games specially for the First Byte Interlace 

All these major software houses are bringing out games that work 
with the First Byte Electron Interface, with no conversion tape needed. 



Alligata 
A & F 

Program Power 
Superior 



Homik 
BugByt* 
Visions 
Virgin 



Aardvark 
Optima 
Postern 
Phoentx 



Software Invasion 

MRM 

Beebug soft 




First Byte Computers; 

10, Castlefields, 

Main Centre, Derby. 

DEI 2PE 

Tel: Derby (0332) 365280 



The First Byte Electron Joystick Interface * available now from all 
good dealers and W. H. Smith. 



A GENUINE FIRST BYTE 
ADD-ON 



OOQQSQSOGQfflOQQEQEC/OQG! 







-- (SUPER-FAST LOADING TIME) 

Qt commodore 



electron b.b.c, micro ivieiviotech 



I]!M^ UI 




4 



£6.95 

( ELECTRON 
and BBC MICRO 
versions £7.95) 

Race along the conveyor belt leaping the 
packages, and shin up the ladders to the 
shopfloor. Pitchfork the Gremlins off the 
walkways, use the poison pouch to trap the 
Giant Rat, and retrieve the oilcan to keep 

the generator topped up. 



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SWOOP, GHOULS AND 

CYBER TRON MISSION 

ARE WINNERS 
AS WELL! 



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pIoIwIeTr 



MICRO POWER LTD.. 

INORTHWOOD HOUSE. NORTH STREET.I 

LEEDS LS7 2AA TEL (0532) 458800 

SELECTIVE BRANCHES OF BOOTS. CO-OP. 

I MENZIES. W. H. SMITH. W0OLW0BTHS AND ALL| 

GOOD DEALERS 

AUTHORS! WE PAY 20% ROYALTIES! 






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